Is it permissible to masturbate due to the wife's poor health and her inability to satisfy the husband's sexual desires?

We ask God to relieve your distress and rectify your wife. You should come to an understanding with her to lighten her burdens by providing a maid or by helping her with household chores and childcare. It is incumbent upon the wife to respond to your call to bed unless there is harm to her in doing so. It is not permissible for you to masturbate with your hand, as it is forbidden. However, it is permissible to masturbate with your wife's hand; there is no sin in that.