Pali, in which only the Buddha delivered his noble messages, appears to have been hallowed as the text of the Buddhavacana. The language of the Buddhavacana is called Pali or Magadhi and sometimes Suddha-Magadhi, presumably in order to distinguish it from Ardha-Magadhi, the language of Jaina Canons. Magadhi means the language or dialect current in the Magadha. In Pali Lexicon, the definition of Pali is given thus: pa paleti, rakkhati ' ti pali. Since it preserves the Buddhavacana (words) in the form of the sacred text, it is called Pali. In fact, the word Pali signifies only "text" "sacred text".
According to the tradition current in Theravada Buddhist countries, Pali is Magadhi, Magadhanirutti, Magadhikabhasa, that is to say, the language of the region in which Buddhism had arisen. The Buddhistic tradition makes the further claim that the Pali Tipitaka is composed in the language used by the Buddha himself. For this reason Magadhi is also called Mulabhasa as the basic language in which the words of the Buddha were originally fixed. However, for Pali now arises the question, which region of India was the home of that language which was the basis of Pali.
Westergrd and E.Kuhn consider Pali to be the dialect of Ujjayini, because it stands closest to the language of the Asokan-inscriptions of Girnar (Guzerat), and also because the dialect of Ujjayini is said to have been the mother-tongue of Mahinda who preached Buddhism in Ceylon (Sri Lanka). R.O. Franke had a similar opinion by different means; and he finally reached the conclusion that the original home of Pali was "a territory, which could not have been too narrow, situated about the region from the middle to the Western Vindhya ranges". Thus it is not improbable that Ujjayini was the centre of its region of expansion. Sten Konow too has decided in favour of the Vindhya region as the home of Pali.
Oldenberg (1879) and E.Muller (1884) consider the Kalinga country to be the home of Pali. Oldenberg thinks that Buddhism, and with it's the Tipitaka, was introduced into Ceylon rather in course of an intercourse between the island and the neighboring continent extending over a long period. However, E.MUller bases his conclusion on the observation that the oldest settlements in Ceylon could have been founded only by the people of Kalinga, the area on the mainland opposite Ceylon and not by people from Bengal and Bihar.
Maurice Winternitz is of the opinion that Buddha himself spoke the dialect of his native province Kosala (Oudh) and it was most likely in this same dialect that he first began to proclaim his doctrine. Later on, however, he wandered and taught in Magadha (Bihar) he probably preached in the dialect of this province. When in course of time the doctrine spread over a large area, the monks of various districts preached each in his own dialect. It is probable that some monks coming from Brahmin circles also attempted to translate the speeches of Buddha into Sanskrit verses. However, the Buddha himself absolutely rejected it, and forbade learning his teachings in any other languages except Magadhi. Here it is related , how two Bhikkhus complained to the Master that the members of the order were of various origins, and that they distorted the words of the Buddha by their own dialect (Sakaya niruttiya). They, therefore, proposed that the words of the Buddha should be translated into Sanskrit verses (Chandaso). The Buddha, however, refused to grant the request and added: Anujanamibhikkhave sakaya niruttiya buddhavacanam pariyapunitum. Rhys Davids and Oldenberg translate this passage by "I allow you, oh brethren, to learn the words of the Buddha each in his own dialect". This interpretation, however, is not accorded with that of Buddhaghosa, according to whom it has to be translated by "I ordain the words of the Buddha to be learnt in his own language (i.e., in Magadhi, the language used by Buddha himself)". In fact, the explanation given by Buddhaghosa is more acceptable, because neither the two monks nor Buddha himself have thought of preaching in different dialects in different cases.
Magahi or Magadhi is spoken in the districts of Patna, Gaya, Hazaribagh and also in the western part of Palamau, parts of Monghyr and Bhagalpur. On its eastern frontier Magahi meets Bengali. Dr.Grierson called the dialect of this region Eastern Magahi (Magadhi). He (Dr.Grierson) has named western Magadhi speeches as Bihari. In this time he includes three dialects, Magahi (Magadhi), Maithili and Bhojpuri. Dr.Grierson, after a comparative study of the grammars of the three dialects, had decided Maithili, Magahi and Bhojpuri as three forms of a single speech. There are four reasons for terming them as Bihari, viz.,
Between Eastern Hindi and Bengali have certain characteristics, which are common to the three dialects.
It becomes a provincial language like Gujarati, Punjabi, Marathi, etc.
The name is appropriate from the historical point of view. Bihar was so named after so many Buddhist Viharas in the state. Ancient Bihar language was probably the language of early Buddhists and Jainas.
It is not a fact that in Bihar there is no literature. In Maithili we have extant ancient literature.
Though Hindi is highly respected as a literary language in Biharyetthe Maithili, Magahi and Bhojpuri languages are deeply entrenched in the emotions of the people. The fact is that Bihari is a speech distinct from Eastern Hindi and has to be classified with Bengali, Oriya and Assamese as they share common descent from Magadhi, Prakrit and Apabhransha. It is clear that an uneducated and illiterate Bihari when he goes to Bengal begins to speak good Bengali with little effort but ordinarily it is not easy for an educated Bihari to speak correct Hindi. Dr.Grierson has inclined to decide that Magadhi was a dialect of Magadha (Bihar) and some parts of West Bengal and Uttar Pradesh.
The area covered by the Buddha's missionary activities included Bihar and Uttar Pradesh including the Nepal Tarai. So it may be assumed that the Buddha spoke in a dialect or dialects current in those regions. Welhelm Geiger considers that Pali was indeed on pure Magadhi, but was yet a form of the popular speech which was based on Magadhi and which was used by Buddha himself. It may be imagined that the Buddha might choose a widespread language which was used or understood by common people in the region, because through which he could propagate his noble teachings to the common people. Thus, Pali or the dialect of Magadha was more probably the language of the common people and also a lingua franca of a large region including mainly Magadha (Bihar).