Is it permissible to shake hands with a foreign woman who is 40 years old, especially if she is the mother of a close friend, and is she considered old enough at this age for it to be permissible to shake her hand?

It is not permissible to shake hands with a non-mahram woman, based on the saying of the Prophet (peace be upon him): "For one of you to be stabbed in the head with an iron needle is better for him than that he should touch a woman who is not permissible for him." It is not permissible to shake hands with them under the pretext of embarrassment. Whoever seeks Allah's pleasure, even if it displeases people, Allah will suffice him against the burden of people. It is appropriate to inform mothers and female friends that shaking hands is not permissible Islamically. One can greet them and inquire about their well-being without shaking hands.