What is owed to a person once they pray with you
Three ordinary things, and then a warning.
مَنْ صَلَّى صَلاَتَنَا، وَاسْتَقْبَلَ قِبْلَتَنَا، وَأَكَلَ ذَبِيحَتَنَا، فَذَلِكَ الْمُسْلِمُ الَّذِي لَهُ ذِمَّةُ اللَّهِ وَذِمَّةُ رَسُولِهِ، فَلاَ تُخْفِرُوا اللَّهَ
Man ṣallā ṣalātanā wa-staqbala qiblatanā wa akala dhabīḥatanā, fa-dhālika-l-muslimu-lladhī lahu dhimmatu-Llāhi wa dhimmatu rasūlih, fa-lā tukhfirū-Llāh
Whoever prays our prayer, faces our direction and eats what we slaughter, that is the Muslim who has the protection of Allah and the protection of His Messenger. So do not betray Allah in what He has guaranteed.
Where this comes from
The test is entirely external and any observer can apply it. And what follows from passing it is not acceptance but a guarantee, which is described as belonging to Allah rather than to the community.
The full narration
Narrated Anas bin Malik:Allah's Messenger (ﷺ) said, "Whoever prays like us and faces our Qibla and eats our slaughtered animals is a Muslim and is under Allah's and His Apostle's protection. So do not betray Allah by betraying those who are in His protection
Source
Ṣaḥīḥ al-Bukhārī · 391
- Agreed upon as authentic (al-Bukhārī / Muslim)