The Pleading Woman - 58:3
Those who have alienated their wives by likening them to their mothers, then turn back on their word, let them free a slave before they have sexual intercourse with their wives. This is what you are advised. Allah is aware of all that you do.
Related to zihar/ alienating/ forbidding wives by replacing them with their mothers:
The Coalition/33:4
Allah has not put two hearts in any man. He has not made your wives your mothers, whom you forbade yourselves by likening them to your mothers, nor has He made your adopted children your own children. All this is but the words of your mouths. Allah speaks the truth and He guides.
The Pleading Woman/58:1
Allah has heard the words of the woman who argued with you about her husband and complained to Allah. Allah has heard all that you two spoke. Allah is All-Hearing, All-Knowing.
The Pleading Woman/58:2
Those among you who alienate their women by likening them to their mothers, know that they are not their mothers. Their mothers are those who gave birth to them. What they say is evil and false. Allah is Forgiving, Forgiving.
The Pleading Woman/58:3
Those who have alienated their wives by likening them to their mothers, then turn back on their word, let them free a slave before they have sexual intercourse with their wives. This is what you are advised. Allah is aware of all that you do.
The Pleading Woman/58:4
Whoever cannot find a slave to free should fast for two consecutive months before sexual intercourse. And he who cannot afford it should feed sixty poor people. You must believe in Allah and His messenger. These are the limits set by Allah. The disbelievers are doomed to a painful punishment.
The Prohibition/66:1
O Prophet, you forbid to yourself what Allah has made lawful for you, just to please your wives. Allah is Forgiving, Merciful.
The Prohibition/66:2
Allah has made known to you the way to make your oaths lawful. Allah is your Mawlana (master). He is All-Knowing, All-Wise.