Make agreements for mutual benefit, be mindful of your words and think before you speak .

This hadith is about a man named 'Abdur-Rahman bin 'Auf who made an agreement with Umaiya bin Khalaf. The agreement was that they would look after each other's relatives and property in different cities. Unfortunately, Umaiya and his son were killed on the day of Badr. Bilal expressed his sorrow at this news by saying "Woe to me if Umaiya remains safe". This hadith teaches us the importance of making agreements for mutual benefit as it can help both parties involved in the exchange. It also teaches us to be mindful of our words and think before we speak as Bilal regretted his words when he heard what happened to Umaiya and his son.