Why "Manasik Japa" is considered the best form of Japa?

Question

As we know a Japa(recitation of Mantras,names of Gods etc) can be of the following 3 types:

1)Vachik-A japa where recitation is loud enough so that both the performer & others(present around him) will be able to hear it.

2)Upanshu-A japa where recitation is like whispering.No one(except the performer himself) will be able to hear the recitation.

3)Manasik-In this case the japa is done silently, completely in mind.While chanting even the lips and tongue are not supposed to touch each other.

We have been repeatedly told by our Gurus that among all the above 3 types of japa its the "Manasik Japa" that's considered the best.

The following sloka from Nrishinga Purana says the same.In fact it says that Manasik japa is the best form of japa followed by Upanshu japa followed by Vachik japa.So,the most beneficial form of Japa is "Manasik" whereas the least beneficial is "Vachik".

Vachikshcha Upanshuscha Manasartrividhah Smritah Trayanaam Japa Yajnanaam Shreyaath Syaduttarottaram||-Meaning-Among the 3 forms of Japa (Vachik,Upanshu & Manasik)the 2nd one is better than the 1st one and the 3rd one is better than the 2nd.

Now,apparently and rationally, it should be the other way round,because Vachik japa requires the most purvanga(preparation) whereas Mansik japa can be done at any place at any conditions(of suchi etc).

Question-Why "Manasik Japa" is considered the best form of Japa?

Answer 1

Either there is some unique benifit of Vashik and upanshu japa or possibly they are stages towards the Manasik japa. I was confused if I should post it or not, it will at least give some direction to why Manasik japa is the best.

In the preface of Nila-Saraswati tantra, S.N.Khandelwal discusses about the three problems (Vighna) faced by Sadhkas in the path of moksha. They are the Oghavighna , Ganavighna and vyuhavigna. The last one is faced in an extremely higher phase of tantric sadhanas. This is what he writes (I am translating):

In the state of Ganavigna, the genrated preception through the means of Gayanendriya and Karmendriya, reverse their orders (reversal). Within the perspective of Tantra, the reason is an attachment towards a group, the Gana-Samuha. Gana-samuha is samasaric in nature and cause attraction towards samasara. The Gana-vigna causes sadhakas attraction towards the Pleasures within the samasara and the attraction towards devotion declines. The end-result is decend in devotion. The best way out is Japa. The Vigna ends as the sadhaka focuses only on the momentum of recitation of the mantra even when, he has deficiencies like Krodha (anger) in his mind. This suggests that the sadhaka should ignore the illusions that rise in the inner world (अन्तरजगत) I.e. he must have no desire to experience them.

In Narayani-tantram as found in Sarvollāsatantram 37-th Ullhasa, Shri-devi asks:

देवेश प्राणनाथेश नमामि चरणाम्बुजे । गोपनीयं कथं प्रोक्तं फलं किञ्च वद प्रभो ॥ ८ ॥

Hey PranVallhab, Salutations to your feet! Why is this secret? What are its benifits? Explain me.

And Shiva answers:

मन्त्र हि गोपनं भद्रं तथा जापकरं शिवे । कारणं हि तथा गोप्यं गोपनीयञ्च मैथुनम्‌॥ ९ ॥ कुसङ्गात् फलहानिः स्यात्‌ सुसङ्गे फलभाग्भवेत्‌ । मुक्त्याकाङ्क्षी महेशानि सड़ त्यक्त्वा क्रियाञ्जरेतू ॥ १० ॥

keeping mantras secret is very auspicious! Japa-karma is secret, Karan is also secret, and Maithun is also secret! Within a bad community the benifits are lost, whereas benefits are gained inside a good community. For a person who desires Mukti, he must abandon the community itself.

However not everything in mind is beneficial:

तन्त्रान्तरे-- मनसापि पठेतू्‌ स्तोत्रं वाचा वापि जपेन्मनुम्‌। उभयोर्निष्फलं विद्यात्‌ भग्नभाण्डोदकं यथा॥ २५ ॥

Reciting the stotras in mind, and performing the japa in loud voice is not at all beneficial. It is as if one keeps water in a broken vessel.

Where the Shrota or listener is important, the mantras are chanted loudly.