It is narrated from a member of Banu Harith bin Ka'b, he says: I was sitting with Sayyiduna Abu Hurairah (may Allah be pleased with him), when a man came to him and asked: Abu Hurairah! Have you forbidden people from fasting on Friday? He said: No, by Allah's life! But by the Lord of this sanctity! I heard the Messenger of Allah (peace and blessings be upon him) say: None of you should ever fast on Friday, except that it coincides with days in which he is already fasting.
Hadith Referenceالفتح الربانی / كتاب الصيام / 3872