dakSiNAmUrti story

[Sudalaimuthu Palaniappan]

I would very much like to know the following details regarding the
dakSiNAmurti story in which ziva teaches four disciples/sages under the banyan
tree.

1.The Sanskrit text that mentions this story for the first time  and the date
of the text

2. The subject that ziva taught these four disciples/sages

3. The names of these four disciples/sages

4. The earliest iconographic representation of this story

Thanks in advance.

Regards
S. Palaniappan