What if a wife says to her husband that when her daughter was born, he did not talk with her for 15 days and that he was sad at that time, and the husband replied that he was not sad and that if he was sad at that time, she is divorced? And what if he did not realize what he said and also forgot about the complete situation of that time?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

The reality of what happened is that this husband conditioned the divorce of his wife on the occurrence of something in the past and doubted its occurrence from him. Divorce does not take place in such a case because in principle the bond of marriage is still intact.

Ar-Ruhaybaani said in Mataalib Uli An-Nuha, which is one of the Hanbali books of Fiqh, "Divorce is not effective due to a doubt about it or a doubt about the condition upon which the husband conditioned the divorce, like if he says, 'if I do not do such-and-such a thing on such-and-such day, then my wife is divorced,' and then he doubted doing that action on that day after that day had passed, then he is not breaking the oath. In principle, the bond of marriage remains effective until what invalidates it is proven without doubt..."

Allah knows best.