Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Saleem that there was a peace treaty between Hazrat Muawiyah and the Romans. Hazrat Muawiyah (may Allah be pleased with him) advanced towards their territory so that when the term of the treaty ended, he could launch a sudden attack on them. Suddenly, from one side of the army, a person came saying, "Fulfill the covenant, do not betray! Fulfill the agreement, do not deceive!" That person was Hazrat Amr bin Abasah. He said, "I heard the Messenger of Allah ﷺ say: Whoever has a treaty with a people should neither tie nor untie its knot until its appointed term has passed, or he should throw back the treaty to them on equal terms."