Musnad Ahmad 30:3674

Yahya ibn Adam narrated to us, Sharik narrated to us, from Abd al-Malik ibn Umayr, from Ziyad al-Harithi, who said: I heard Abu Hurayrah, and a man said to him: "Are you the one who forbids people from fasting on Friday?" He said: "Yes, by the Lord of this Kaaba, yes, by the Lord of this Kaaba" — three times — "I heard Muhammad, may Allah bless him and grant him peace, say: 'None of you should fast on Friday alone, unless there are days with it.'" "And I saw Muhammad, may Allah bless him and grant him peace, praying while his sandals were upon him, then he would depart while they were upon him."