How can a man abandon his wife in bed when he cannot bear abandonment and does not wish to commit what is forbidden, and is it permissible for him to masturbate while imagining his wife, and what is the wisdom behind abandonment in bed?

Abandonment (hajr) is not the first step in treating nushuz (disobedience/rebelliousness on the part of the wife); rather, it is preceded by admonition. It should only occur when nushuz has actually taken place, and its purpose is to deter the woman from it and discipline her. If this outcome is not expected from it, then it is not prescribed. It is a right of the husband, so he may choose to forgo it. Its meaning has been said to be: abstaining from intercourse, or abandoning her bed, or speaking harshly, or not speaking to her, or abandoning cohabitation with her when she desires it. The husband is not permitted to satisfy his desires through masturbation.