Is it permissible to fast on Saturday if a person fasts on Friday?

The questioner : Shaykh, regarding fasting on Friday, the Prophet (peace and blessings be upon him) mentions in a hadith that one should fast a day before it or a day after it. If a person fasts on Friday, is it permissible for him to fast on Saturday if he did not fast on Thursday?

The Shaykh : No, it is not permissible.

The questioner : It is not permissible either.

The Shaykh : Saturday is not to be fasted except in the case of an obligatory fast, as you heard in the hadith.

The questioner : I mean, Shaykh, if you please, regarding the hadith about Saturday, some scholars said that it is weak.

The Shaykh : Where is Muhammad?
The student : Here on the left.

The Shaykh : Who is Muhammad?
The student : ... al-Khatib with his family, with the women.

The Shaykh : Okay, where is he?
The student : Here on the left.

The questioner : Surat al-Waqi'ah ... .

The Shaykh : Is it authentic or weak?

The questioner : May Allah reward you with good.

The Shaykh : And you, the first day ... and the second from here ... but all these four days are covered by the chapter of permissibility, it is clear.