Chapter: The Prophet (saws) used to send commanders and messengers one after another

Allah's Messenger (ﷺ) sent a letter to Khosrau and told his messenger to give it first to the ruler of Bahrain, and tell him to deliver it to Khosrau. When Khosrau had read it, he tore it into pieces. (Az-Zuhri said: I think Ibn Al-Musaiyab said, "Allah's Messenger (ﷺ) invoked Allah to tear them (Khosrau and his followers) into pieces."

Allah's Messenger (ﷺ) said to a man from the tribe of Al-Aslam, "Proclaim among your people (or the people) on the day of 'Ashura' (tenth of Muharram), 'Whosoever has eaten anything should fast for the rest of the day; and whoever has not eaten anything, should complete his fast.' "