What is the ruling of Fasting (Sunnah) on Friday & Saturday?

With regard to a question on Sunnah fasting in General, and instances when fasting on Friday and Saturday are alright.

Firstly: Fasting every other day. The Prophet ﷺ said that this is the most virtuous fast. Abdullah bin Amr رضي الله عنه narrated that the Prophet ﷺ said: ( إن أفضل الصيام صيام داود : كان يصوم يوماً ويفطر يوماً) Indeed the best of the fasting is the fast of Dawud عليه السلام. He fasted one day and would not fast the following day”.

Meaning: Fasting every other day. Here, there are no prohibitions in fasting on Friday or Saturday when the alternate fasting day coincides with the day of fasting. Because his action is based upon the Hadeeth. He is a person fasting on alternative days. For, under no circumstance, he is fasting on a particular day of the week. Know that, fasting every other day is characterised as the best fast.

And when Prophet ﷺ advised Abdullah bin Amr رضي الله عنه wouldn’t he know that the person fasting every other day would fast on Saturday, Friday, Tuesday… or any other day? In spite of this, after he said and agreed to fast in this manner, is there any chance to differ?

Second: Fasting the 13th, 14th and 15th of the lunar(Hijri) month. Many Ahādeeth had been reported about this as well. It is mentioned in a narration in صحيح الترغيب Saheeh at-Targheeb:

كان رسولُ اللهِ صلَّى اللهُ عليهِ وسلَّم يأمُرنا بصيامِ أيامِ البِيضِ ثلاثَ عشرَ وأربعَ عشرَ وخمسَ عشرَ قال وقال : هو كهيئةِ الدهرِ

“Fasting the days of Ayyam al-Beed (the 13th 14th and 15th of the lunar month) was commanded by the Prophet ﷺ to us companions. And he ﷺ said that it is like fasting the whole year through”.

Dear brother! I’ll ask a question. When the Prophet ﷺ said this, wouldn’t a Friday or a Saturday or a Tuesday fall on any of the 3 consecutive days? Therefore, his intention is not Friday. Not even Wednesday. Since his intention is these 3 days, there is no prohibition in this.

Next is the issue of combining intention.

Since his intention is to fast Sunnah fasting on all these days, scholars state that two intentions can be combined together.

The former Mufti of Saudi Arabia, Imām ibn Baaz رحمه الله said, “Since it is a Sunnah fasting, praise be to Allāh, a Monday falls on one of the 3 days (13th,14th or 15th). That’s a virtuous act on top of another virtuous act الحمد لله praise be to Allāh….” This means that the intention can be combined and that he will get reward for fasting both days. Hope this issue is clear.