[Avodah] what's the source?

[Saul.Z.Newman at kp.org]

online someone noted in his shul  a collector stating ----

And then he said that it is a minhag to give Matanos La'Evyonim on Taanis 
Esther and on Purim (and then he repeated that it is a minhag to give on 
Taanis Esther), and minhag yisroel torah hee, customs of Israel are like 
actual Torah (and should be treated like obligations). 

--what's the source for the minhag  of  matanos leevyonim on taanis 
esther?
[i will not ask my usual question about the 5th mitzva of  purim ]
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.aishdas.org/pipermail/avodah-aishdas.org/attachments/20110317/37ba1f9f/attachment.htm>