1. In a lease contract or a business transaction, none of the transacting parties should violate the agreed terms of the contract or transaction. If both parties agreed upon a certain price and a certain quality or quantity of the sale item, or in a lease contract, both agreed upon leasing the premises for a specific period at an agreed rate, then both parties should abide by the agreement.
عن حكيم بن حزام رضي الله عنه أن النبي صلى الله عليه وسلم قال البيعان بالخيار ما لم يتفرقا فإن صدقا وبينا بورك لهما في بيعهما وإن كذبا وكتما فعسى أن يربحا ربحا ويمحقا بركة بيعهما (صحيح البخاري رقم 2079)
Hazrat Hakeem ibn Hizaam (Radhiyallahu Anhu) reports that Rasulullah (Sallallahu Alaihi Wasallam) said: “The two transacting parties have an option (to back out of the sale) as long as they do not conclude the sale (with mutual acceptance). If they (the purchaser and seller) are truthful to each other and disclose the faults (of the merchandise), they will be granted barkat (blessing) from Allah Ta‘ala in their business transaction. However, if they lie to each other and conceal the faults (of the merchandise), then perhaps they could earn some profit through the transaction, however they will lose the blessing of the transaction.”