Is it obligatory to verbalize the salam, or is gesturing with the hand or using the car horn sufficient?

Question:
It is sometimes observed that car owners use the car horn as a salam when they pass by their friends or companions; they honk the horn to make a sound as a salam, and the others respond in kind. Sometimes it is accompanied by a hand gesture. Is it obligatory to verbalize the salam along with this gesture? As for the one who responds, is he required to verbalize the response as well, or is it sufficient to use these gestures? And does this have a basis in the Shari'ah?

Answer:
Gestures and the sound of the horn are not sufficient in place of the verbal salam; rather, one must verbalize the salam. It is recommended (mustahabb) for the one who initiates to verbalize the salam, and it is obligatory (wajib) for the one who responds to verbalize the response. This is because initiating the salam is a recommended practice (sunnah), and responding to it is obligatory. The sound of the horn or a hand gesture is not sufficient for this. Rather, the sound of the horn or the hand gesture serves as a sign or notification to the other person to prepare for the salam that his Muslim brother is delivering to him. Therefore, a hand gesture or the car horn is not sufficient in place of verbalizing the salam; rather, it serves as a notification to someone far away who cannot hear the salam. However, verbalizing the salam is required alongside it, and the prescribed nature of the salam is only achieved through verbalization. Yes. May Allah bless you and reward you with good.