What is the ruling on a man shaking hands with a woman, and what are the views of the Four Imams and the majority of scholars on this?

Shaking hands with a non-mahram woman is forbidden by the consensus of the four madhhabs, and many religious texts indicate this. Among them is the saying of the Messenger of Allah, peace and blessings be upon him: "For one of you to be stabbed in the head with an iron needle is better for him than to touch a woman who is not lawful for him." And Aisha, may Allah be pleased with her, said: "The hand of the Messenger of Allah, peace and blessings be upon him, never touched the hand of any woman at all, except that he would take their oath of allegiance with words." This prohibition includes shaking hands with a barrier or shaking hands with an old woman, except in cases of necessity, such as medical treatment if no woman is available to perform it.