Musannaf Ibn Abi Shayba 33:1346

Ibn Fudayl narrated to us, from his father, from Isma'il, from al-Hasan, who said: When he would recite this verse: "Indeed, Allah has purchased from the believers their lives and their properties," he said: Their lives, He created them, and their properties, He provided them. "They fight in the cause of Allah, so they kill and are killed. [It is] a true promise [binding] upon Him in the Torah and the Gospel."