Is it allowed to fast on 13th of Dhul Hijjah?

Question

Is it true that there are four days of celebration of Eid Adha? Does that imply we can't fast for 4 days whether we sacrifice an animal or not?

Narrated Uqbah ibn Amir: The Prophet (ﷺ) said: The day of Arafah, the day of sacrifice, the days of tashriq are (the days of) our festival, O people of Islam. These are the days of eating and drinking. [Sunan abi Dawod and other Versions in other Sunan Books]

Nubaisha al-Hudhali reported Allah's Messenger (ﷺ) as saying: The days of Tashriq are the days of eating and drinking. [Sahih Muslim]

It was narrated from Abu Hurairah that the Messenger of Allah (ﷺ) said: “The days of Mina (11th, 12th, and 13th of Dhul-Hijjah) are days of eating and drinking.’” [Sunan ibn Majah]

Related Question but didn't get my answer: What days are you meant to fast in dhul hijjah

Answer 1

No, according to the majority view it is not permissible to fast on the 10^th, 11^th, 12^th and 13^th of Dhu’l-Hijjah, and along-with 1^st Shawwaal this makes the fives days of the year when fasting is not allowed.

The eleventh to the thirteenth date are known as the Days of Mina or the Days of Tashriq, and the Prophet ﷺ forbade fasting on these days:

بينما نحن بمنى إذا علي بن أبي طالب رضي الله عنه، يقول: إن رسول الله صلى الله عليه وسلم، قال: " إن هذه أيام أكل وشرب، فلا يصومها أحد " واتبع الناس على جمله يصرخ بذلك

Whilst we were in Mina, I saw Ali bin Abi Talib (رضي الله عنه) say: The Messenger of Allah (ﷺ) said: “These days are for eating and drinking, so no one should fast these days.” And he went around to the people on his camel, shouting that.

^{— Musnad Ahmad}

كل فهذه الأيام التي كان رسول الله صلى الله عليه وسلم يأمرنا بإفطارها وينهانا عن صيامها ‏.‏ قال مالك وهي أيام التشريق

Eat, as these are the days in which the Messenger of Allah (ﷺ) ordered us to eat our meals and prohibited us from fasting. Malik said: They were the days of Tashriq.

^{— Abu Dawud}

An exception that is held by some of the madhabs and not others is the case of people on whom sacrifice was obligatory (Hajj tamattu') but they were unable to find an animal. They are required to fast for some days (see Quran 2:196) and this can include the days of Mina as has been recorded from some of the sahaba by e.g. Bukhari. While a third madhab allows for fasting on other than the two Eids.

Ref: https://islamqa.info/en/answers/66193