What is the ruling on greeting with a gesture for one who is able to speak, and are deaf people considered to be falling short if they greet with a gesture?

Uttering the Salaam is emphasized, and it is disliked to merely gesture, except for someone who is unable to speak, such as a mute. There is no blame upon him for merely gesturing, as Allah does not burden a soul beyond its capacity. As for a deaf person who can speak, it is incumbent upon him to utter the Salaam, and it is not permissible for him to merely gesture. It is appropriate to combine utterance and gesture for someone who gives Salaam to a deaf person, so that he may understand. If he does not combine them, he does not deserve a reply. The gesture of a mute person takes the place of verbal expression in giving and returning the Salaam.