*Prohibition of Treachery and Breaking one's Covenant*
Abu Hurairah (May Allah be pleased with him) reported: The Prophet صلى الله عليه وسلم said, "Allah, the Exalted, says: 'I will contend on the Day of Resurrection against three (types of) people: One who makes a covenant in My Name and then breaks it; one who sells a free man as a slave and devours his price; and one who hires a workman and having taken full work from him, does not pay him his wages.'''
[Al-Bukhari].
Commentary: This Hadith highlights the importance of fulfillment of promise, the prohibition of the sale of a free person, and the payment of due wages to the labourers