Ibn `Abbas (May Allah be pleased with them) reported:
The Messenger of Allah (Sallallahu Alaihi Wasallam) said,
"If I remain alive till the next year,
I shall also observe fast on the ninth of Muharram.''
[Muslim].
Commentary:
Some people think these words stand to mean that `he will observe Saum
on the 9th of Muharram only. But this interpretation does not agree with
other Ahadith. In order to oppose the Jews, he (Sallallahu Alaihi Wasallam)
resolved to observe one more Saum with that of 10th of Muharram and ordained
it for the Muslims. In this connection, we have quoted above the authority
from Musnad Ahmad. Hence, the meanings we have given in the translation of
the text are correct.