The Ruling on Returning the Greeting on Behalf of the Group

The Shaykh : One aspect of this is that if a Muslim offers the greeting to a group of Muslims and one of those in the group returns it, then it is dropped from the rest; it is not obligatory for every individual in that group to whom the Muslim greeted to return it individually.
There is no doubt that it is better for each of them to return it if they desire good; because the Muslim’s saying: as it came in the authentic hadith, ten good deeds are recorded for him, and if he says: then twenty, and if he adds: then thirty. So if you return it, even if the Muslim was one person greeting a group and you were among them, you have benefited from these good deeds. But the question is whether it is obligatory for every individual in the group to return the greeting of the one who greeted?
The answer is: It is not obligatory, but it is obligatory for one of them; it is a collective obligation (fard kifayah). If some of them perform it, it is dropped from the rest. However, it is better for the rest to return the greeting all together. This differs from responding to the sneezer; for it is obligatory for every person who hears a Muslim sneeze and follow it with praise of Allah (Mighty and Majestic) that every person who hears his praise should respond to him, as will be discussed in some of the paragraphs in the hadith, which are explicit in responding to the sneezer.
Then, regarding offering the greeting, some scholars restrict it, saying for example, for example, one does not greet the one praying, one does not greet the one reciting, one does not greet the one eating, drinking, who is eating and drinking and the like. These opinions, although they were said by a group who have their knowledge and virtue, they differed and did not agree, so we have a wide scope to choose from what they differed in what is closest to the truth and to the correct.