The Book of Oaths (Kitab Al-Aiman)

Muslim :: Book 15 : Hadith 4067

Abu Huraira reported Allah's Prophet (may peace be upon him) as saying that Sulaiman b. Dawud, the Apostle of Allah, observed: I will have an intercourse with seventy wives during the night; all of them will give birth to a male child who will fight in the cause of Allah. His companion or the ang I said to him: Say," If God wills." But he (Hadrat Sulaimin) did not say so, and he forgot it. And none of his wives gave birth to a child, but one who gave birth to a premature child. Allah's Messenger (may peace be upon him) said: Had he said Insha' Allah (if God so will). he would not have failed and his desire would have been materialised.

Source materials are from the University of Southern California MSA site
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