Imam Ahmad was asked about a man who does that with his hand. He disliked it strongly, and said: I hate it, it is not from the action of the people of muruwwah (dignity). He held it forbidden in principle, citing the verse: "And those who guard their private parts except from their wives... but whoever seeks beyond that, those are the transgressors" (al-Mu'minūn 5–7). He permitted it only in cases of severe necessity to a man who feared he would otherwise fall into zinā and could not marry — as a lesser of two harms, not as something originally permissible.