The Prophet ﷺ said: When one of you comes to an assembly, he should give a salutation and if he feels inclined to get up, he should give a salutation, for the former is not more of a duty than the latter.  

قَالَ رَسُولُ اللَّهِ ﷺ إِذَا انْتَهَى أَحَدُكُمْ إِلَى الْمَجْلِسِ فَلْيُسَلِّمْ فَإِذَا أَرَادَ أَنْ يَقُومَ فَلْيُسَلِّمْ فَلَيْسَتِ الأُولَى بِأَحَقَّ مِنَ الآخِرَةِ