Is it permissible to fast on the Prophet's birthday if it falls on a Friday?

We have previously ruled that celebrating the Prophet's birthday (Mawlid) is an innovated bid'ah. Some of those who celebrate it have worsened the matter by disliking fasting on this day, even though the Prophet, peace and blessings be upon him, was asked about fasting on Monday and he said: "It is the day on which I was born, and on which revelation was sent to me," narrated by Muslim.

By doing so, they have contravened the Sunnah in two ways: First, by innovating a festival that Allah and His Messenger did not legislate. Second, by disliking fasting, even though the Prophet, peace and blessings be upon him, fasted on it. The Prophet, peace and blessings be upon him, used to fast on Mondays and did not designate a single day out of every year. So, whoever wishes to emulate his Sunnah should fast on Mondays in Rabī' and in other months. Designating the twelfth of Rabī' al-Awwal for fasting is contrary to the Sunnah, and the contravention becomes greater if it falls on a Friday, as it is forbidden to single out Friday for fasting.