From the Etiquettes of the Gathering.

The Shaykh : On an occasion like this, I used to remind myself of the same thing. I used to say to some people who find certain old or new legal rulings burdensome—old in terms of legislation and new in terms of transmission to some people—such as, for example, his saying (peace and blessings be upon him) . The one who has not accustomed himself to this noble Prophetic guidance says, "This is a long business; every time one enters and leaves, it is 'Peace be upon you, peace be upon you.'" So I used to answer these people by saying, "What is wrong with this? It is only that we have not accustomed ourselves to this Sunnah. Otherwise, this is a new and very great Islamic manifestation: that a person says 'Peace be upon you' every time he enters and 'Peace be upon you' every time he leaves. What is wrong with it? It contains good supplication: 'May Allah be upon you, what Allah willed.' That is a good thing. And we also speak of a manifestation, if this naming is correct here, which is another one: his saying (peace and blessings be upon him) . In another hadith, . This narration is authentic and clarifies that responding to the sneezer is not like returning the greeting or delivering the greeting; one person suffices in this. So if a person enters and says 'Peace be upon you,' and one of the people sitting there responds, the obligation falls off the others. But without a doubt, it is better for each of them to respond. As for sneezing, it is not like that. . This objection was also raised: 'My brother, this will become a commotion in the gathering. One person sneezes, and it is 'May Allah have mercy on you, may Allah have mercy on you, may Allah have mercy on you.' We said to him, 'What is wrong with this and that? Every time one enters and leaves, it is 'Peace be upon you,' and every time one person sneezes, you find the whole gathering rising in one movement: 'May Allah have mercy on you, may Allah have mercy on you, Glory be to Allah.' This is not acceptable. And it is not acceptable for people who are called the Druwish or the people of the paths to sit and say 'Allah, Allah, Allah' without anyone objecting. But here, the difference is between this innovated remembrance and that prescribed remembrance."