Arjuna prayed to Goddess Durga on the advice of Lord Krishna, before commencement of the war on the tenth day. And Goddess Durga answered Arjuna’s prayers and blessed him.
The event is described as under:-
Understanding (the measure of) Partha's devotion, Durga who is always graciously inclined towards mankind, appeared in the firmament and in the presence of Govinda, said these words.
'Within a short time thou shalt conquer thy foes, O Pandava. O invincible one, thou hast Narayana (again) for aiding thee. Thou art incapable of being defeated by foes, even by the wielder of the thunderbolt himself.'
The prayer is commonly known as Arjuna Krutha Durga Sthuthi. The Arjuna Krita Durga Stuti is as:
श्रीअर्जुन उवाच -
नमस्ते सिद्ध-सेनानि, आर्ये मन्दर-वासिनी ।
कुमारी कालि कापालि, कपिले कृष्ण-पिंगले ॥१॥
Salutations to the commander of Sidhas, who is noble and lives in forest of Mandara, Who is the virgin Kali who wears the skulls , who is brown , black and tawny.
भद्र-कालि! नमस्तुभ्यं, महाकालि नमोऽस्तुते।
चण्डि चण्डे नमस्तुभ्यं, तारिणि वर-वर्णिनि ॥२॥
I salute the gracious Kali , I salute the great Kali,
I salute the killer of violent Chanda ,
Who has blessed colour and makes you cross.
कात्यायनि महा-भागे, करालि विजये जये ।
शिखि पिच्छ-ध्वज-धरे, नानाभरण-भूषिते ॥3॥
Oh greatly valorous daughter of Katyayana ,
Oh terrible achiever of victory and triumph,
Oh Goddess who has the flag of peacock feathers,
And who is decorated with different type of ornaments.
अटूट-शूल-प्रहरणे, खड्ग-खेटक-धारिणे ।
गोपेन्द्रस्यानुजे ज्येष्ठे, नन्द-गोप-कुलोद्भवे ॥४॥
O you that wields an awful spear, the holder of sword and shield, O you that were born as the younger sister of the chief of cow-herds (Lord Krishna), O eldest sibling, born in the family of the cowherd Nanda!
महिषासृक्-प्रिये नित्यं, कौशिकि पीत-वासिनि ।
अट्टहासे कोक-मुखे, नमस्तेऽस्तु रण-प्रिये ॥५॥
O you who are always fond of buffalo's blood, born of Kusika's clan,
dressed in yellow robes, having assuming the face of a wolf you
devoured the Asuras! I bow to you who are fond of battle!
उमे शाकम्भरि श्वेते, कृष्णे कैटभ-नाशिनि ।
हिरण्याक्षि विरूपाक्षि, सुधू्राप्ति नमोऽस्तु ते ॥६॥
I salute Uma , Shakambari, the white one , the black one , one who killed Kaitabha,
One who has golden eyes, one who has slanted eyes and one has great eyes of smoke colour.
वेद-श्रुति-महा-पुण्ये, ब्रह्मण्ये जात-वेदसि ।
जम्बू-कटक-चैत्येषु, नित्यं सन्निहितालये ॥७॥
You are Veda, you are sruthi, you do greatly blessed deeds,
You are the spirit of Brahma , you were born from Vedas,
You are daily present in the temple with rose apple tree.
त्वं ब्रह्म-विद्यानां, महा-निद्रा च देहिनाम् ।
स्कन्ध-मातर्भगवति, दुर्गे कान्तार-वासिनि॥८॥
You are the knowledge about Brahman among knowledges.
You are the great sleep among the living beings,
You are the Bhagwathi who is the mother of Skanda,
And you live on mountains which are inaccessible.
स्वाहाकारः स्वधा चैव, कला काष्ठा सरस्वती ।
सावित्री वेद-माता च, तथा वेदान्त उच्यते ॥९॥
You the sound of Swaha, Swadha the food of manes,
You are the superior time, You are Saraswati ,
You are Savitri , the mother of Vedas ,
And you are also the inner soul of the Vedas.
स्तुतासि त्वं महा-देवि विशुद्धेनान्तरात्मा ।
जयो भवतु मे नित्यं, त्वत्-प्रसादाद् रणाजिरे ॥१०॥
Oh Great Goddess , I am praying with a pure and clean heart,
Let victory be mine daily by your blessing , Oh goddess of the battle field.
कान्तार-भय-दुर्गेषु, भक्तानां चालयेषु च ।
नित्यं वससि पाताले, युद्धे जयसि दानवान् ॥११॥
Oh Goddess who leads your devotees through thorny fearful mountains,
Oh Goddess you win over the asuras who daily live in the nether world.
त्वं जम्भिनी मोहिनी च, माया ह्रीः श्रीस्तथैव च ।
सन्ध्या प्रभावती चैव, सावित्री जननी तथा ॥१२॥
You are the destroyer, the enchanter , the illusion the chants Hree and Shree
You are the dusk, you are bearer of luster , Savithri and also the mother.
तुष्टिः पुष्टिर्धृतिदीप्तिश्चन्द्रादित्य-विवर्धनी ।
भूतिर्भूति-मतां संख्ये, वीक्ष्यसे सिद्ध-चारणैः ॥१३॥
You are contentment, health , speed and luster, You increase the effectiveness of Sun and Moon,
You are wealth of those who prosper and numerous Sidhas and Charanas look forward to you.
Reference:-Mahabharata, Book-6, Bhishma Parva,Bhagvat Gita Parva:- http://www.sacred-texts.com/hin/m06/m06023.htm
Link for the prayer:- http://stotraratna.sathyasaibababrotherhood.org/g191.htm