Sahih Muslim Book 004, Hadith Number 1111.
Chapter : Permissibility of carrying children in prayer.
Abu Hazim is reported on the authority of his father: Some people came to Sahl b. Sa'd and began to differ about the wood of which the (Prophet's pulpit was made. He (Sahl b. Sa'd) said: By Allah, I know of which wood it is made and who made it, and the day when I saw the Messenger of Allah (may peace be upon him) seated himself on it on the first day. I said to him: O Abu Abbas (kunyah of Sabl b. Sa'd), narrate to us (all these facts), He said: The Messenger of Allah (may peace be upon him) sent a person to a woman asking her to allow her slave, a carpenter, to work on woods (to prepare a pulpit) so that I should talk to the people (sitting on it). Abu Hazim said: He (Sahl b. Sa'd) pointed out the name of (that lady) that day. So he (the carpenter) made (a pulpit) with these three steps. Then the Messenger of Allah (may peace be upon him) commanded it to be placed here (where it is lying now). It was fashioned out of the wood of al-Ghaba. And I saw the Messenger of Allah (may peace he upon him) standing upon it and glorifying Allah and the people also glorified Allah after him, while he was on the pulpit. He then raised (his head from prostration) and stepped back (on his heels) till he prostrated himself at the base of pulpit, and then returned (to the former place and this movement of one or two steps continued) till the prayer was complete. He then turned towards the people and said: O people, I have done it so that you should follow me and learn (my mode of) prayer.