Answered by Shaykh Amjad Rasheed
Is it permissible to use a vibrator on the clitoris of one’s wife during intercourse?
What appears to me from the sayings of our Imams is that it is permissible, as long as [the vibrator] is in the hand of the husband, and there is no harm entailed to the wife. However, it is not permissible for the wife to use it by herself to excite passion, since it would be like masturbation by hand, which is haram, and Allah knows best. I asked our shaykh, the investigating faqih, Muhammad al-Khatib al-Hadrami al-Shafi’i about this question, and he confirmed the above mentioned.