He—may Allah have mercy on him—also said:

Concerning the words of Allah Most High:

“O you who believe, fulfil your covenants.”

It has been said that these refer to what Allah and His Messenger have commanded. The Prophet, may Allah bless him and grant him peace, placed this verse at the beginning of the letter he wrote to Amr ibn Hazm when he appointed him governor of Najrān. The letter to Amr contains prescribed obligations, blood-money payments, and practices made obligatory by revealed law.

Allah also says to the believers:

“Remember Allah’s favour upon you and His covenant by which He bound you when you said, ‘We hear and obey.’”

The Quran commentators have mentioned that this verse was revealed concerning the Prophet’s taking the pledge of allegiance from the Ansār on the night of al-Aqabah. The Prophet, may Allah bless him and grant him peace, had bound them by a covenant to what was already obligatory by Allah’s command: to listen to him and obey. Allah reminded them of that covenant so that they would fulfil it, although it imposed nothing beyond what Allah’s command had already made obligatory.

In this verse, He commanded them to remember His favour upon them and His covenant. Thus, He mentioned both grounds of obligation, for the obligation established by revealed law is also binding by virtue of His lordship—that is, His bestowal of blessings upon them. Hence the hadith states:

“Love Allah for the blessings with which He sustains you.”

For this reason, authors writing on the fundamentals of religion customarily begin by discussing the first blessing Allah bestowed upon His servants and the first duty incumbent upon them, and they discuss