Prophet Sulaymān ibn Dawūd (peace be upon him) said to his interlocutor that he would have intercourse with seventy wives of his. It was permissible to combine such a number of wives in Sulaymān's time, or it was something specific to him. His intention was that each woman would give birth to a boy would who fight in the cause of Allah. His interlocutor told him to say: "Allah willing!" But he forgot to do so. He had intercourse with his wives, but none of them gave birth, except for one woman who gave birth to a stillborn. The Prophet (may Allah's peace and blessings be upon him) said that if Sulaymān had said "Allah willing", he would have fulfilled his oath and realized his wish.