Dought & clear,- Recommendation to fast Taasoo’a’ with ‘Ashoora’

I want to fast 'Ashoora' this year, but some people told me that the
Sunnah is to fast the day before as well (Taasoo'a'). Is there any
report that this was the teaching of the Prophet (peace and blessings
of Allaah be upon him)?.
Praise be to Allah
'Abd-Allaah ibn 'Abbaas (may Allaah be pleased with him) said: When
the Messenger of Allaah(peace and blessings of Allaah be upon him)
fasted on the day of 'Ashoora and told the people to fast, they said,
"O Messenger of Allaah, this is a day that is venerated by the Jews
and Christians." The Messenger of Allaah(peace and blessings of Allaah
be upon him) said, "Next year, if Allaah wills, we will fast on the
ninth day." But by the time the following year came, the Messenger of
Allaah(peace and blessings of Allaah be upon him) had passed away.
Narrated by Muslim, 1916.
Al-Shaafa'i and his companions, Ahmad, Ishaaq and others said: It is
mustahabb [recommended] to fast both the ninth and the tenth, because
the Prophet(peace and blessings of Allaah be upon him) fasted the
tenth and intended to fast the ninth.
Based on this, there are different ways of fasting 'Ashoora', the
least of which is to fast the tenth only, but it is better to fast the
ninth as well. The more one fasts in Muharram, the better.
If one were to ask, what is the wisdom behind fasting the ninth as
well as the tenth? The answer is:
Al-Nawawi (may Allaah have mercy on him) said: The scholars among our
companions and others said that there are several reasons for
recommending fasting on the ninth day (Tasoo'a'):
1 – The intention behind it is to be different from the Jews who limit
their fasting to the tenth day. This was narrated from Ibn 'Abbaas.
2 – The intention was to join the fast of 'Ashoora' to another day,
just as it is not allowed to fast on a Friday on its own [but it is
allowed if one fasts the day before or the day after as well].
3 – The idea is to be on the safe side and make sure one is fasting on
the tenth, in case the moon sighting was not accurate and what people
think is the ninth is actually the tenth.
The strongest of these reasons is in order to be different from the
People of the Book. Shaykh al-Islam Ibn Taymiyah said: The
Prophet(peace and blessings of Allaah be upon him) forbade resembling
the People of the Book in many ahaadeeth. For example, he said
concerning 'Ashoora': "If I live until next year I will certainly fast
the ninth."Al-Fataawa al-Kubra, part 6.
Ibn Hajar (may Allaah have mercy on him) said, commenting on the
hadeeth "If I live until next year I will certainly fast the ninth":
His concern to fast the ninth may be understood as meaning that he
would not limit himself to that, rather that he would add it to the
tenth, either to be on the safe side, or to be different from the Jews
and Christians, which is more likely to be correct; this is what may
be understood from some of the reports narrated by Muslim."
FromFath al-Baari, 4/245.