Wifāq ul Ulāma (SA) ASSOCIATION OF SOUTH AFRICAN 'ULAMA
1. From an entire group of people, if one person among them makes salaam to someone they meet, his salaam will suffice on behalf of the entire group. Similarly, if a person meets a group of people and greets them with salaam, the reply of one person among them will suffice on behalf of the entire group.
عن على بن أبى طالب رضى الله عنه (قال أبو داود رفعه الحسن بن على) قال: يجزئ عن الجماعة إذا مروا أن يسلم أحدهم ويجزئ عن الجلوس أن يرد أحدهم (ابو داود رقم 5212)
Hazrat Ali (Radhiyallahu Anhu) reports that Rasulullah (Sallallahu Alaihi Wasallam) said: “It suffices on behalf of an entire group of people when they pass by someone that one person among them makes salaam (to the person they meet), and it suffices on behalf of a group of people seated that one among them replies to the salaam (of the person who greets them with salaam).”