Muwatta 1606

Malik says of a man who makes ila against his wife and then divorces her, so that the four months end before her divorce waiting period does: these are two divorces if he is stopped and does not return. If her divorce waiting period ends before the four months, the ila is not a divorce, because the four months after which he would be stopped have passed when she is no longer his wife. ¹

Belongs to the Muwatta, Book of Divorce. Source: the Muwatta. Mentions Malik ibn Anas. Built on in the chapters on ila.