Hello,

> What is origin of Pali
> Is its origin is Magadhi

It's origin is Magadhi. Not Magadhi of Asokan edicts (third century
b.c.), but the earlier Ardha-Magadhi.

See: http://en.wikipedia.org/wiki/Magadhi_Prakrit

You can find an interesting discussion at:
http://www.lioncity.net/buddhism/index.php?showtopic=21867

> or it is a pidgen language which was create
> by Budh scholars for writing of Lord Budha's education

Pali evolved with time, and one can find in the Pali Canon the early
stratas with archaic word forms, and the later stratas with stylized
grammar. So scholars contributed to the evolution of Pali.

It's interesting that the word forms that evolved later did not find
their way in the earlier texts. For example, the later evolved form
'kilesa' is not found in the Sutta-pitaka. In Sutta one can find only
the early form 'upakkilesa'.

> What was the mother tongue of lord Budha

It was a language very similar to Pali.

The language preserved in Jain texts, Aredha-Magadhi
http://en.wikipedia.org/wiki/Jain_Prakrit
which was spoken in about the same area at the same time, is very
similar to Pali.

Metta, Dmytro