(16–17) “Say to those Bedouins who stayed behind, ‘You will be called to fight a people of great military might. You will fight them unless they embrace Islam. If you obey, Allah will grant you a fine reward; but if you turn away as you did before, He will punish you with a painful punishment.’ * There is no blame upon the blind, nor upon the lame, nor upon the sick. Whoever obeys Allah and His Messenger, He will admit him into gardens beneath which rivers flow; but whoever turns away, He will punish him with a painful punishment.”
After mentioning that the Bedouins who stayed behind had refrained from jihad in His cause, offered excuses without justification, and sought to accompany the believers only when there was no armed resistance or fighting but merely the prospect of spoils, Allah Most High tested them, saying: “Say to those Bedouins who stayed behind, ‘You will be called to fight a people of great military might.’” That is, the Messenger and those who succeed him in his role—the Rightly Guided Caliphs and leaders—will call you. These people are the Persians, the Byzantines, and others like them.
“You will fight them unless they embrace Islam.” That is, it will be one or the other—and this is precisely what occurred. While the Muslims were fighting those peoples, when the latter still retained their strength and might, they would not agree to pay the jizya (tribute). They would either embrace Islam or fight while remaining as they were. But once the Muslims had thoroughly subdued them and they became weak and humbled, their might vanished, and they then had either to embrace Islam or pay the jizya.
“If you obey” the one calling you to fight these people, “Allah will grant you a fine reward.” This is the reward that Allah and His Messenger have ordained for jihad in the cause of Allah. “But if you turn away as you did before” from fighting those whom the Messenger called you to fight, “He will punish you with a painful punishment.” This verse demonstrates the virtue of the Rightly Guided Caliphs, who called the Muslims to fight formidable peoples, and that they must be obeyed in this regard.
He then mentioned the grounds that excuse a person from setting out for jihad, saying: “There is no blame upon the blind, nor upon the lame, nor upon the sick”—that is, for remaining behind from jihad because of the disabilities that prevent them from taking part.
“Whoever obeys Allah and His Messenger” by carrying out what they command and avoiding what they prohibit, “He will admit him into gardens beneath which rivers flow,” containing all that souls desire and eyes delight in. “But whoever turns away” from obedience to Allah and His Messenger, “He will punish him with a painful punishment.” Thus, all happiness lies in obedience to Allah, while misery lies in disobeying and opposing Him.