Musannaf Ibn Abi Shaybah 18970 — A man writing his wife's divorce

Al-Hasan (may Allah have mercy on him) said: If a person wrote a divorce addressed to his wife, then it occurred to him to hold back the letter, then as long as he does not speak it, it has no standing. If he sent the letter to the wife, she counts her waiting period ('iddah) from the day the letter reaches her.