What scriptures describe the origin of Arjuna's monkey flag?

Question

In the Mahabharata, Arjuna is frequently described as Kadipdhvaja, or the one who has a monkey flag. In the popular imagination, this flag is associated with Hanuman. And this association does have a scriptural basis; in Bhima's encounter with Hanuman, which I discuss in my answer here, Hanuman tells him that during the battle of Kurukshetra he will emit shouts from the flag of Arjuna's chariot to intimidate the Kauravas. See this chapter of the Vana Parva of the Mahabharata:

From fraternal feeling and affection, I will do good unto thee, by diving into the army of thy foes copiously furnished with arrows and javelins. And, O highly powerful one, O hero, when thou shall give leonine roars, then shall I with my own, add force to shouts. Remaining on the flagstaff of Arjuna's car will I emit fierce shouts that will damp the energy of thy foes. Thereby ye will slay them easily.

But my question is, what is the origin of Arjuna's monkey flag? Was it always a flag associated with Hanuman, or did Hanuman just enter it during the Mahabharata war?

The story I've always heard about the monkey flag is the one told in the Bengali Mahabharata and in this excerpt from the Amar Chitra Katha comic book "Tales of Arjuna". Arjuna once goes on a pilgrimage to Rameshwaram, at the southern tip of India, and sees Rama's bridge. He boasts that if he were Rama, he wouldn't need the help of the Vanaras in building a bridge, he could make a sturdy bridge to Lanka with his arrows. Now Hanuman happens to be in the area, so he takes the form of a small monkey and makes a wager with Arjuna that if Arjuna builds a bridge of arrows, he wil be able to break it. The conditions are that if Arjuna wins then the monkey becomes his slave, and if the monkey wins then Arjuna has to commit suicide. In any case, Arjuna builds a bridge of arrows, but then the monkey just touches it and it breaks. Arjuna is devastated, and is about to jump into a funeral pyre when a Brahmana boy comes there and suggests that Arjuna and the monkey have a rematch, with the boy being the judge. They agree, and Arjuna makes another bridge. This time Hanuman is not able to break it, even when he becomes gigantic. It is at that moment that Hanuman realizes that the boy is nothing but his beloved Rama, and Arjuna realizes the boy is his beloved Krishna. In any case, Krishna resolves the dispute by telling Hanuman to appear on the flag of Arjuna's chariot, to fulfill the conditions of the bet.

But I'm not aware of any scriptures that describe this story. And also, as I discuss in this question, Arjuna received his chariot from Varuna the ocean god, who got it from Chandra the moon god. And when he got it, it already had the monkey flag; see this chapter of the Adi Parva of the Mahabharata:

The smoke-bannered celestial [Agni] welcoming with reverence [Varuna] the ruler of the waters, that fourth of the Lokapalas, said unto that eternal god of gods, "Give me without loss of time that bow and quiver, and that ape-bannered car also, which were obtained from king Soma." ... Varuna also gave two inexhaustible quivers, and he also gave a car furnished with celestial weapons and whose banner bore a large ape.... It had been made by Viswakarman, the architect of the universe and one of the lords of creation, after severe ascetic meditation. Its splendour, like that of the sun, was so great that no one could gaze at it. It was the very car from which the lord Soma had vanquished the Danavas. Resplendent with beauty, it looked like an evening cloud reflecting the effulgence of the setting sun. It was furnished with an excellent flag-staff of golden colour and great beauty. And there sat upon that flag-staff a celestial ape of form fierce like that of a lion or a tiger. Stationed on high, the ape seemed bent upon burning everything it beheld.

So did the chariot have the monkey flag from the time it was made by Vishwakarma and used by Chandra, and if so who does it depict? Was it always meant to depict Hanuman, or does it depict some other "celestial ape" and did Hanuman just enter into the flag during the Mahabharata war? It could depict Vrishakapi, an ape described in the Vedas who was a ally of Indra but also had an affair with Indra's wife Shachi.

In any case, does anyone know any scriptures which describe either Arjuna's encounter with Hanuman or some other origin of Arjuna's monkey flag?

EDIT: The user sv. just pointed me to this chapter of the Virata Parva of the Mahabharata, where Dronacharya recognizes Arjuna while the latter is dressed like a woman. Here's what Dronacharya says:

O offspring of the Ganges, apparelled as a woman, this is Kiriti called after a tree, the son of the enemy of the mountains, and having on his banner the sign of devastator of the gardens of Lanka's lord.

Now the translator claims this verse does not appear in all manuscripts, but assuming it's authentic it's further evidence that Arjuna's monkey flag was always associated with Hanuman, who is the one who burned the gardens of Ravana. But on the other hand, it makes it all the more strange that the flag was already on the chariot when Varuna gave it to Arjuna.

Answer 1

This story is found in Sarga 18, Kanda IX of Ānanda Rāmāyaṇa.

In my knowledge, this is the only sanskrit-text based reference for the detailed account of Arjuna's encounter with Hanumāna and Kṛṣna, in the Rāmeśvaram, and why Arjuna is known as Kapi-dhvaja.

Sarga Eighteen, Manohara kāṇḍa, Ānanda Rāmāyaṇa

अष्टादशः सर्गः
( हनुमानजीके द्वारा अर्जुननिर्मित शरसेतुभंजन )

श्रीविष्णुदास उवाच
कपिध्वजोऽर्जुनश्चेति मया पूर्व श्रुतं गुरो । तन्नामकारणं मां त्वं विस्तराद्त्तुमर्हसि ॥१॥

श्रीरामदास उवाच
सम्यक् पृष्टं त्वया शिष्य सावधानमनाः शृणु। द्वापरान्तं भाविकथां त्वां वदामि चमत्कृताम् ।।२।। एकदा कृष्णरहितोऽर्जुनः स्यन्दनसंस्थितः । ययावरण्ये विचरन्मृगयार्थ हि दक्षिणाम् ॥३॥ एकाकी सूतसंस्थाने स्थित्वा तत्कृत्यमावरन् । हत्वा वने मृगान्धन्वी मध्याई स्नातुमुद्यतः ॥४॥ ययौ रामेश्वरं सेतो धनुष्कोट्यां विगाह्य च । मध्याह्नकृत्यं संपाद्य पुनः स्यंदनसंस्थितम् ॥५॥ अब्धेस्तटे विचचार किंचिद्र्वसमन्वितः । एतस्मिन्नतरेऽाण्ये पर्वतोपरि संस्थितम् ।।६।। ददर्श मारुति वीरः सामान्यकपिरूपिणम् । राम रामेति जल्पंत पिंगलोमधरं शुभम् ॥७॥ तमर्जुनोऽब्रवीद्वाक्यं किं नामास्ति कपे तव । तदर्जुनवचः श्रुत्वा विहस्य कपिरब्रवीत् ॥८॥ यत्प्रतापाच्च रामेण शिलाभिः शतयोजनम् । बद्धोऽयं सागरे सेतुस्तं मां त्वं विद्धि वायुजम् ।।२।। इति तद्गर्थसहितं वाक्यं श्रुत्वाऽर्जुनस्तदा । गर्वाद्विहस्य प्रोवाच मारुतिं पुरतः स्थितम् ॥१०॥ दृथा रामेण सेवर्थ श्रमः पूर्व कृतस्त्वयम् । कथं तेन शरैः सेतुं कृत्वा कार्य कृतं न हि ॥११॥ तदर्जुनवचः श्रुत्वा मारुतिः प्राह तं पुनः । मत्तुन्यकपिभारेण शरसेतुः पयोनिधौ ॥१२॥ न्युब्जिष्यतीति मत्वा तं नाकरोद्रघुनन्दनः । तत्कपेचनं श्रुत्वाऽर्जुनो मारुतिमद्रवीत् ॥१३॥ कपिभारायदा सेतुजेले मग्नो भविष्यति । धनुर्विद्या धन्विनः का तदा वानरसत्तम ॥१४॥ अधुनाऽहं करिष्यामि शरसेतुं तवाग्रतः । त्वं तस्योपरि नृत्यादि कुरुष्वात्र यथासुखम् ।।१५।। धनुर्विद्या ममाद्य त्वं कपे पश्यतुमर्हसि । तदर्जुनगिरं श्रत्वा तमाह सस्मितः कपिः ॥१६॥ ममाघ्रधंगुष्ठभारेण अरसेतुस्त्वया कृतः। चेन्मन्नः स्यात्समुद्रे हि तदा कार्य त्वयाऽत्र किम्॥१७॥ तत्कपैर्वाक्यमाकर्ण्य सोऽर्जुनः प्राह तं पुनः । यदि मनः शरसेतुस्त्वद्वारात्तीह कपे ॥१८॥ विशाम्पत्रानलं सत्यं त्वं चाप्पद्य पणं वद । तत्प्रतिज्ञा कपिः श्रुत्वाऽर्जुनं वचनमब्रवीत् ॥१५॥
मया स्वांगुष्ठभारेण वत्सेतुश्चेन लोपितः । तर्हि त्वद्ध्वजसंस्थोऽहं तव साहाय्यमाचरे ॥२०॥ तथाऽस्त्वित्यर्जुनः प्राह टणत्कृत्य महदनुः । निर्ममे शरसंजालैः सेतुं दृढतरं धनम् ॥२२॥शतयोजनविस्तीर्ण सागरस्योर्ध्वतः स्थितम् । तं सेतुं मारुतिदृष्ट्वार्जुनाग्रेऽङ्गुष्ठभारतः ।।२२।। अकरोत्सागरे मग्नं क्षणमात्रेण लीलया । तदा देवाः सगंधर्वाः किन्नरोरगराक्षसाः ॥२३॥ विद्याधराश्वाप्सरसः सिद्धाद्या गगनस्थिताः । मारुतिं बर्जुनस्याग्रे ववर्ष: पुष्पवृष्टिमिः ॥२४॥ तत्कर्मणाऽर्जुनश्चापि चितां कृत्वाऽब्धिरोधसि । निवारितोऽपि कपिना देह त्यक्तं समुद्यतः ॥२५॥ एतस्मिन्नन्वरे कृष्णस्तं प्राह बटुरूपवृक् । ज्ञात्वाऽर्जुनमुखात्सर्व पूर्ववृत्तं पणादिकम् ॥२६॥ उभाभ्यां यद्यच्चरितं पूर्व तच्च वृथा गतम् । साक्षित्वेन विना कर्म सत्य मिथ्या न बुध्यते ॥२७॥ साक्षित्वेनाधुना मेत्र युवाभ्यां कर्म पूर्ववत् । कर्तव्यं तदहं दृष्ट्वा सत्यं मिथ्या वदाम्यहम् ।।२८|| तद्बटोर्वचनं श्रुत्वा द्वाबूचतुस्तथेति च । ततश्चकार गांडीवी शरसेतुं हि पूर्ववत् ।।२९।। सेतोरंतर्गतं चक्रं श्रीकृष्णचाकरोत्तदा । ततः स्वांगुष्ठ भारेण कपिः सेतुं प्रपीडयत् ।।३०।। सेतुं दृढ़ कपिञ्जत्वा पादजानुकरादिभिः । बलेन पीडयामास स सेतुस्तैश्चचाल न ॥३१॥ तदा तूष्णीं हनुमान्स मंत्रयामास चेतसि । पूर्व मांगुष्ठ भारात्सेतुश्चाब्धौ विलोपितः ॥३२॥ हस्तादिभिः कथं नायमिदानी न विलुप्यते । कारणं बटुरेवात्र बटुर्नायं हरिस्त्वयम् ।।३३।। अस्तीत्यहं विजानामि स्मृत पूर्ववरादिकम् । मद्गर्वपरिहारोऽद्य कृष्णेनानेन कर्मणा ॥३४॥ कुतोऽस्त्यत्र क कृष्णाग्रे मन्मर्कटसुपौरुषम् । इति निश्चित्य मनसि कपिः सोऽर्जुनमब्रवीत् ॥३५॥ जितं त्वया बटोयोगात्तव साहाय्यमाचरे । नायं वटुस्त्वयं कृष्णः सेतुचक्रप्रवेशकत ॥३६॥ स्वत्साहाय्यार्थमायानः सत्यं ज्ञातो मयाऽर्जुन | अनेन रामरूपेण त्रेतायां मे वरोऽपितः ॥३७॥ दास्यामि दर्शनं तेऽहं द्वापरे कृष्णरूपवृक् । तत्सत्यं वचनं चाद्य कृतं त्वत्सेतुहेतुतः ॥३८॥ इत्यर्जुनं कपिर्यावदत्रवीत्तावदप्रतः । बटुरेवाभवत्कृष्णः पीतवासा धनप्रमः ॥३९।। तद्दर्शनोर्ध्वरोमाऽभूत्प्रणनामांजनीसुतः । आलिंगिनोऽपि कृष्णेन स मेने कृकृतत्यताम् ।।४।। चक्रं ययौ यथास्थानं श्रीकृष्णस्याज्ञया तदा । सागरेण स्वकल्लोलः शरसेत विलोपितः ॥४१॥ तदाऽर्जुनो गर्वहीनो मेने कृष्णेन जीवितः । कृष्णस्तदाऽर्जुनं प्राह त्वया रामेण स्पर्द्धितम् ।।४२।। हनूमता धनुर्विद्या तबातोऽत्र मृषा कृता । यत्प्रतापादिति गिरा त्वयाऽपि वायुनन्दन । ४३|| रामेण स्पर्धितं यस्मात्तस्मादर्जुन संजितः । अतः परं वीतगर्वस्त्वं मां मज निरन्तरम् ॥४४॥ इत्युक्त्वा मारुतिं पृष्ट्वाऽर्जुनेन तत्पुरं ययो । अतः कपिध्वजश्चति जनैरर्जुन ईर्यते ॥४५।। इति भाविकथा पृष्टा त्वया साऽपि मयोदिता । किमग्रे श्रोतकामोऽसि तत्पृच्छस्व वदामि ते ॥४६॥

विष्णुदास उवाच
गुरोऽधुना राघवस्य वैकुंठारोहणोत्सवम् । मां वदस्व सविस्तारं येनाहं तोषमाप्नुयाम् ।।४७॥ श्रीरामदास उवाच पूर्णकांडं तावाद्याहं वदिष्यामि शृणुष्व तत् ।

Summarized Translation by me:

• Viṣṇudāsa requests Rāmadasa to recount the story of why Arjuna is called Kapi-dhvaja.

• Rāmadasa recounts - Once, Arjuna went deep into forests alone (without Kṛṣna at chariot's helm), straight into the south direction. Having killed some animals in ākheṭa (आखेट), he reached for the dhanuṣakoṭitīrtha (धनुषकोटितीर्थ) to take a bath, at the Rāmeśvaram and started strolling around the place, filled with ego on archery skills.

• There Arjuna saw an ordinary-looking monkey (Hanumān) sitting on a mountain, busy chanting Rāma's name. Arjuna questioned the monkey about his identity. Replying to Arjuna, the monkey replied laughing, that he's the one who helped Śri Rāma construct the 100 yojanas floating bridge on the sea, he's Vāyu-Putra Hanumān.

• To the monkey's haughty claim, Arjuna also retorts with pride, asking why didn't Śri Rāma make the bridge from arrows-sticks, which Hanumān refutes saying such a bridge would have collapsed under the weight of the large vānara-army.

• Arjuna taking a jibe at Hanumān's reasoning proposes to construct an arrow-bridge by himself which will be conducive to Hanumān's playful activities. Hanumān challenges Arjuna as to what if, the bridge were to collapse just with the monkey's toe? Arjuna bet a wager assuring to enter a pyre if monkey succeed. Hanumān reciprocates betting lifetime servitude to Arjuna by sitting on his chariot's flag.

• Arjuna constructs an arrow-bridge as promised, but obviously, Hanumān drowns the bridge using just his toe, much to Arjuna's dismay, who now starts preparing to enter a pyre.

• Just in time, Sri Kṛṣna appears, disguised as a brahmachārī Brāhmiṇa, and advises both Arjuna and Hanumān to re-match the bet. Both agree, and Arjuna constructs yet another bridge, but this time Kṛṣna supports the bridge from below using his Sudarśana Chakra, and obviously, this time Hanumān fails to drown the bridge, however hard he may try.

• Hanumān mentally deliberates on this inconsistency, and quickly realizes the real identity of the Brāhmiṇa. Kṛṣna reveals his true form and Hanumān falls at his feet.

• Kṛṣna explains to Arjuna that since he in his ego dared to compare himself with Śri Rāma, therefore Hanumān voided his dhanur-vidyā (archery-skills). Similarly, since Hanumān boasted about helping Śri Rāma - thus he was defeated by Arjuna (in his second attempt).

• And thus, losing, wager to Arjuna (with Kṛṣna's apt intervention though), Hanumān occupied Arjuna's flag, and thus Arjuna came to be known as kapi-dhvaja (Monkey-Bannered).

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