Tafsir of Al-Anfal 8:71

"And if they intend to betray you..."

(And if they intend)—meaning the captives—(to betray you)—meaning to violate what they covenanted with you regarding the payment of ransom, or [to violate the agreement] that they would not return to fight against you nor support the polytheists. It is also possible that the intended meaning is: if they intend to break that which they pledged to you regarding Islam, to commit apostasy, and to prefer the religion of their forefathers, (then they have already betrayed Allah before) through disbelief and the violation of His covenant taken from every rational being; indeed, some have claimed that this is the closer interpretation.

(So He empowered [you] over them)—meaning, He made you capable of dealing with them just as you saw at Badr. Thus, if they repeat the betrayal, know that Allah the Exalted will also empower you over them; the object [of the verb] is elided. His statement, Glory be to Him, (then they have already betrayed Allah before) stands in the place of the response [to the conditional "if"]. This sentence is presented by Him, the Exalted, as a means to console the Prophet, peace and blessings be upon him, by way of promising him victory and threatening them.

(And Allah is All-Knowing)—so He knows what is in their intentions and the punishment they deserve—(All-Wise)—He does everything He does in accordance with the requirements of His profound wisdom.