Is it permissible to fast on Saturday voluntarily, combined with Sunday?

The questioner: And what about Saturday and Sunday together voluntarily, is it permissible?

The Shaykh : No, Saturday, it is not permissible to fast on Saturday, and this...
The questioner: Voluntary, voluntary.

The Shaykh : Yes
The questioner: This is voluntary, I am saying.

The Shaykh : Excuse me, please be like you were just now, three or four voices, I need to understand one voice. Fasting on Saturday voluntarily is not permissible, and it is only permissible in the obligatory, either in the month of Ramadan, or making up what is upon a person, or a vow upon a person. And you must ask why it is not permissible. He (peace and blessings be upon him) said: The bark of a tree, the peel, you see the grapevine, the grapes, how this peel separates from it. This is an exaggeration in breaking the fast. That is, to realize his breaking of the fast in response to the command of the Prophet (peace and blessings be upon him) to break the fast on Saturday.
And I on this trip was perhaps asked this question dozens of times, but this was naturally from men, and for the first time it is directed to me from women. Therefore, I see myself compelled to detail this issue somewhat, which is difficult for those accustomed to fasting, especially the virtuous days like fasting Ashura, for example, and fasting the Day of 'Arafah, and the like. It may happen that the Day of Ashura is a Saturday, and it may happen that the Day of 'Arafah is a Saturday. This occurs sometimes, so it is difficult for people if they are accustomed to fasting the Day of 'Arafah and the Day of Ashura; it is difficult for them to leave fasting because it coincides with Saturday.
So here I say to them, clarifying that there is a jurisprudential rule that we must know and keep always in mind, which is: if a prohibition comes regarding something and an encouragement for that same thing at the same time, like fasting, for example. We are now in the fasting of the Day of Ashura or 'Arafah, so there is great encouragement in fasting these two days. It is agreed that it came on a Saturday, the Day of Saturday, which is prohibited to fast on, while the Day of Ashura or 'Arafah is encouraged to fast on. So here there is a conflict between a prohibition and a command, even if it is only on the level of recommendation. At that time, the jurisprudential rule says, and this is their text: "If a prohibitive and a permissive conflict, the prohibitive is given precedence over the permissive" "If a prohibitive and a permissive conflict, the prohibitive is given precedence over the permissive" The prohibitive here is understood by the prohibitive, the prevention, meaning this is the expression of the scholars. So his saying prohibited from fasting on Saturday, fast on the Day of 'Arafah, fast on the Day of Ashura, this is the permissive. So the permissibility conflicted with the prohibition. What does the scholar do? He gives precedence to the prohibition over the permissive.
The example now is a person who has the habit of fasting on Monday or Thursday. The Day of 'Id comes on a Monday or Thursday. Does he fast it? He does not fast it. Why? The prohibitive is given precedence over the permissive. A person has the habit of fasting one day and breaking the fast on another. He broke the fast, for example, on Tuesday. The Day of 'Id comes on Wednesday. According to the system followed, he has to fast on Wednesday, but that day was the Day of 'Id. Does he fast it? No. If the prohibitive and the permissive conflict, the prohibitive is given precedence over the permissive. This is a very important rule. So here now, do not fast on Saturday. The Day of Ashura comes on a Saturday. What do we do? We give precedence to the prohibitive over the permissive. The Day of 'Arafah comes on a Saturday. We do not fast it, because it is necessary to give precedence to the prohibitive over the permissive.
And finally, I say a very important word, which is that some people are convinced in their consciences by this speech from the scientific side, but their emotions and their habit of fasting prevent them from digesting this speech, even though it is clear. So I say to these people: do not think that if the Day of Saturday conflicts with the Day of Ashura, or the Day of Saturday conflicts with the Day of 'Arafah, and we leave fasting this day because it is a Saturday, that we have lost the virtue of the Day of Ashura or the virtue of the Day of 'Arafah. No, we have not lost anything. And the proof is that he (peace and blessings be upon him) said: So the difference between one whose habit is to fast the Day of Ashura because it expiates the previous year, or one whose habit is to fast 'Arafah because it expiates the previous and coming year, and it happens that that was the Day of Ashura, so he did not fast. He did not lose anything because he left fasting the Day of Ashura or the Day of 'Arafah for the sake of Allah. So Allah compensates him with something better than it. So there is no loss in that case. Yes.
The questioner: But he can fast the day before it, for example, meaning, for the sake of... a Saturday came and the Day of 'Arafah is, for example, the eighth and ninth.

The Shaykh : Yes, I am telling you and those like you of the women and men, you memorized something and things were absent from you that you did not memorize. What did the hadith say?
The questioner: In the obligatory.

The Shaykh : Except, complete what?
The questioner: In the obligatory.

The Shaykh : So the picture that you are now presenting is obligatory.
The questioner: No.

The Shaykh : The hadith is very clear.
The questioner: Okay, it might be a Friday.
Another questioner: I once had a debt, an Islamic debt, so I started on Friday... this is forbidden, you fast on Friday only if there is a Thursday before it and after that... so the important thing is, they said it is forbidden and... in the Haram, they said it is possible even if Friday alone is permissible, no, it is not necessary that there is a Thursday before it or a Saturday after it.

The Shaykh : This is in the obligatory, as you are saying, it is permissible to fast on a Friday to make up an obligatory fast.
The questioner: To make up.

The Shaykh : Yes, this has no obstacle.
The questioner: Even if it is a vow.

The Shaykh : Yes
The questioner: Meaning, a debt is upon me.

The Shaykh : Yes, this is permissible. I am now asking your permission.
The questioner: May Allah reward you with good.

The Shaykh : On the way, there is no one, perhaps.
The questioner: Ask a quick question, possible.

The Shaykh : Yes, until they do not establish the prayer.