Pali language is scriptures of Theravada Buddhism........

Pali language:     

Pāli is the language of the scriptures of Theravada Buddhism, (the Pāli Canon or the Tipitakain Pāli), which were written in Sri Lanka during the 1st century BC. Pāli has been written in a variety of scripts, including Brahmi, Devanāgarī and other Indic scripts, and also using a version of the Latin alphabet devised by T. W. Rhys Davids of the Pāli Text Society. 

 The Chant of Metta:

The name Pāli means "line" or "(canonical) text", and probably comes from the commentarial traditions, wherein the "Pāli" (in the sense of the line of original text quoted) was distinguished from the commentary or the vernacular following after it on the manuscript page. There are a number of ways to spell the name of the language: Pali, Pāli, Paḷi, Pāḷi, all four of which are found in textbooks.

Today Pāli is studied mainly by those who wish to read the original Buddhist scriptures, and is frequently chanted in rituals. There are non-religious text in Pāli including historical and medical texts. The main areas where Pāli is studied are Myanmar, Sri Lanka, Thailand, Laos and Cambodia.

Manopubbangamā dhammā, manosetthā manomayā; Manasā ce padutthena, bhāsati vā karoti vā, Tato nam dukkhamanveti, cakkam'va vahato padam.

Translation:

Mind precedes all mental states. Mind is their chief; they are all mind-wrought. If with an impure mind a person speaks or acts suffering follows him like the wheel that follows the. Translated by AcharBuddharakkhita. 

Many Theravada sources refer to the Pāli language as "Magadhan" or the "language of Magadha". This identification first appears in the commentaries, and may have been an attempt by Buddhists to associate themselves more closely with the Mauryans. The Buddha taught in Magadha, but the four most important places in his life are all outside of it. It is likely that he taught in several closely related dialects of Middle Indo-Aryan, which had a high degree of mutual intelligibility. There is no attested dialect of Middle Indo-Aryan with all the features of Pāli. Pāli has some commonalities with both the Ashokaninscriptions at Girnar in the West of India, and at Hathigumpha, Bhubaneswar, Orissa in the East. Similarities to the Western inscription may be misleading, because the inscription suggests that the Ashokan scribe may not have translated the material he received from Magadha into the vernacular of the people there.  

Whatever the relationship of the Buddha's speech to Pāli, the Canon was eventually transcribed and preserved entirely in it, while the commentarial tradition that accompanied it (according to the information provided by Buddhaghosa) was translated into Sinhalese and preserved in local languages for several generations.  In Sri Lanka, Pāli is thought to have entered into a period of decline ending around the 4th or 5th century (as Sanskrit rose in prominence, and simultaneously, as Buddhism's adherents became a smaller portion of the subcontinent), but ultimately survived.

The work of Buddhaghosa was largely responsible for its reemergence as an important scholarly language in Buddhist thought. The Visuddhimagga and the other commentaries that Buddhaghosa compiled codified and condensed the Sinhalese commentarial tradition that had been preserved and expanded in Sri Lanka since the 3rd century BCE.

 Buddha puja in Pali language:    

 

Pali is a literary language of the Prakrit language family and was first written down in Sri Lanka in the first century BCE. Despite scholarship on this problem, there is persistent confusion as to the relation of Pāḷi to the vernacular spoken in the ancient kingdom of Magadha, which was located around modern-day Bihār.

 Metta chanting:   

 

Pāli, as a Middle Indo-Aryan language, is different from Sanskrit, not only with regard to the time of its origin but as to its dialectal base since a number of its morphological and lexical features betray the fact that it is not a direct continuation of Ṛgvedic Vedic Sanskrit; rather it descends from a dialect or number of dialects that were, despite many similarities, different from Ṛgvedic.