Musnad Ahmad 955:3

Abu al-Walid and 'Affan narrated to us, they said: 'Ubayd Allah ibn Iyad ibn Laqit narrated to us, I heard Iyad ibn Laqit saying: I heard Layla, the wife of Bashir, that she asked the Prophet, peace and blessings of Allah be upon him: "Should I fast on Friday and not speak to anyone on that day?" The Prophet, peace and blessings of Allah be upon him, said: "Do not fast on Friday unless it is among days that are [already] one of them, or in a month. As for not speaking to anyone, by my life, that you speak with kindness and forbid what is evil is better than that you remain silent."