Assalaamu alaykum wa rahmatullaahi wa barakaatuhu. If some poor people are eating and I pass by them and they invite me to join them, should I do so?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

According to the majority of the scholars, it is not obligatory to accept the invitation to a meal except for the wedding banquet.

If someone invites you to eat with him, you are not obliged to do so regardless of whether he is poor or rich. However, if you know that accepting his invitation and joining him would please him and will not cause any harm to him, then it is an act of the Sunnah to accept his invitation.

Allah knows best.