That is: those who stay behind are not equal to those who strive, and the negation of parity is plain; for the combatant has offered up his life and his wealth for Allah, whereas the one who remains at home is burdened by fear—except for those whom Allah has exempted when He says, “except those who are disabled,” meaning those who would be harmed were they to go forth for battle. These fall into three categories mentioned by Allah: “There is no blame upon the blind, nor upon the lame, nor upon the sick,” and likewise those who have nothing to spend or whose bodies are too weak, for Allah says, “There is no blame upon the weak, the sick, or those who can find nothing to spend, provided they are sincere to Allah and His Messenger; no reproach attaches to those who excel in good, and Allah is All-Forgiving, Most Merciful.” The third group comprises those who remain behind to gain understanding of the religion, as He says, “It is not for all the believers to go forth together; yet why should not a band from each group stay behind to gain deep knowledge of the religion and to warn their people when they return to them, so that they may take heed?”

Thus, the excused are three types:

1. Those who are disabled or physically frail.
2. Those who have no wealth to contribute.
3. Those who remain to acquire religious understanding.

Such people are pardoned, either because their staying serves an interest greater than that of going to battle—these are the students of sacred knowledge—or because they have a legitimate impediment that prevents them from joining the fighting.

Concerning Allah’s words, “Those believers who sit at home—other than those who are disabled—are not equal to those who strive in the path of Allah with their wealth and their lives,” the strivers hold the higher rank. In this verse Allah negates equality among the believers and shows that they are not all on the same level, just as He says: