The greeting when someone comes to a gathering

Abu Hurayra reported that the Messenger of Allah ﷺ said, "When one of you comes to a gathering, he should give the greeting. If he leaves, he should give the greeting. Neither is more of a duty than the other."

حَدَّثَنَا أَبُو عَاصِمٍ، عَنِ ابْنِ عَجْلاَنَ، عَنْ سَعِيدٍ الْمَقْبُرِيِّ، عَنْ أَبِي هُرَيْرَةَ قَالَ: قَالَ رَسُولُ اللهِ ﷺ: إِذَا جَاءَ أَحَدُكُمُ الْمَجْلِسَ فَلْيُسَلِّمْ، فَإِنْ رَجَعَ فَلْيُسَلِّمْ، فَإِنَّ الأُخْرَى لَيْسَتْ بِأَحَقَّ مِنَ الأولَى.