“Glory and praise be to You, O Allah; I bear witness that there is no god but You; I seek Your forgiveness and repent to You,” he will be forgiven for whatever took place in that gathering. Related by al-Tirmidhi, who said: a ḥasan ṣaḥīḥ ḥadīth.

[Commentary]
Among the etiquettes of assemblies is what the author cites from ʿAmr ibn Shuʿayb, from his father, from his grandfather (may Allah be pleased with him), that the Prophet ﷺ said: “It is not lawful for a man to separate two people except with their permission.” That is, if you come upon two people sitting next to each other, do not insert yourself between them unless they permit you to do so—either by explicit speech, such as one of them saying, “Come and sit here,” or by action, when they move apart to signal that you may sit between them. Otherwise, do not separate them, for this is poor manners if you merely tell them to make room, and actual harm if you sit down and crowd them.

Another point of etiquette is that a person should sit wherever the gathering ends, as mentioned earlier. Likewise, it is impermissible to sit in the middle of a circle. If you see a group sitting in a ring—whether around someone teaching them or someone addressing them—the key point is that they form a circle, so you must not seat yourself in its center