Musannaf Ibn Abi Shaybah 19343 — Those who said zihar has no time

Al-Hakam (may Allah have mercy on him) and Hammad (may Allah have mercy on him) said: If a man says of his wife that she is to him like his mother's back for four months, and the four months pass, this is ila'. And if he says that she is like his mother's back and then leaves her for a year, this is not ila'.