Sa'd b. Abu Waqqas told of a man who came to God's Messenger and said that he withdrew his penis from his wife. He asked him why he did that and the man replied that he feared for her child, so God’s Messenger said, “If that were injurious it would injure the Persians and the Greeks.”*
* This is explained as referring to a woman who is suckling a child, and the fear that the child, would be injured if she became pregnant.
He said that when God’s Messenger was asked about withdrawing the penis he replied, “The child does not come from all the liquid, and when God intends to create anything nothing can prevent Him.”
I was with God’s Messenger along with some people when he was saying, “I intended to prohibit suckling during pregnancy* but I considered the Greeks and the Persians and saw that they suckled their children during pregnancy without any injury being caused to their children thereby.” Then they asked him about withdrawing the penis and God’s Messenger replied, “That is the secret burying alive” and reference is made to it in the words, “When the girl buried alive will be asked (Al-Qur’an 81:8).”
*(Ghila. It means either suckling during pregnancy, or intercourse with a woman while she is suckling a child.
We went out with God’s Messenger on the expedition to the B. al-Mustaliq (an expedition in 6 A.H) and took some Arab women captive, and we desired the women, for we were suffering from the absence of our wives. We liked withdrawing the penis and wanted to do so, but we asked ourselves whether we could do it when God’s Messenger was among us before asking him. So we asked him about that and he replied, “It does not matter if you do not do it, for every soul that is to be born up to the day of resurrection will be born.”