«وَشَرُّ الْأَضْيَافِ مَنْ سَامَ التَّكْلِيفَ»
The worst guest is one who demands burdensome obligations.
Al-aḍyāf is a plural of “guest”; sāma here means to impose or demand; al-taklīf refers to a burdensome duty.
The guest juxtaposes the host’s generosity with the visitor’s responsibility to show consideration. It is a character’s ethically coloured speech, not a newly stated formal legal ruling.