Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) forbade fasting on the day of Friday: except if one fasts a day before it or a day after it as well.

Sayyiduna Bashir (may Allah be pleased with him) says: I asked the Messenger of Allah (peace and blessings be upon him): I will fast on Friday and will not speak to anyone on that day? The Prophet (peace and blessings be upon him) said: "Do not fast on Friday, unless you fast on several days and Friday happens to be among them (then there is no harm). As for your issue of not speaking to anyone, by my life! Speaking good and forbidding evil is better for you than remaining silent."

It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Do not fast on the day of Friday, unless you fast a day before it or a day after it as well."