Tafsir of Al-Anfal 8:15

(O you who have believed): This is an address to the believers concerning a universal ruling applicable to incidents and wars that would occur. It is presented amidst the narrative to manifest its importance and to urge adherence to it.

(When you meet those who disbelieve as a Zahf [advancing army]): Al-Zahf, as Al-Raghib stated, is a movement involving the dragging of the buttocks, similar to the movement of a child before he walks, or a fatigued camel. It also refers to an army when it is numerous and its movement is consequently sluggish. Others have said: It is crawling; it is said "the child zahafa" when he creeps on his buttocks bit by bit. Then, the name was applied to the massive army heading toward the enemy because, due to its size and density, it appears as if it is crawling; for the whole is seen as one connected body, and its movement is perceived as extremely slow, even though, in reality, it is extremely fast. As the Glorious Exalted One says: "And you see the mountains, thinking them solid, while they pass as the passing of clouds." A poet of theirs said: "And a massive force, like a mountain, you think it is stationary due to its density, while the mounts are moving at a steady pace." It is pluralized as Zuhuf because it has departed from its source-meaning. Its accusative state is either as a hal (state) from the object of laqaytum (you meet)—meaning, "while they are advancing toward you"—or as an emphatic infinitive for a hidden verb that acts as the hal, meaning "they are crawling a crawl." It has been suggested that it could be a hal from the subject, or from both the subject and the object together. This has been objected to, saying it is refuted by the Almighty’s saying: (Then do not turn your backs to them), as there is no meaning in restricting the prohibition of turning away to the enemy’s prior movement toward them or their numerical superiority; rather, the enemy’s movement toward them and their numerical superiority are, by custom, the very causes for turning away and the reasons necessitating the prohibition. Carrying it to signify what would happen to them on the day of Hunayn, when they turned away while being twelve thousand, is far-fetched.

The response given is that what is meant by Zahf is nothing more than walking for battle, without considering numerical superiority or inferiority. Walking for this purpose is named as such because, when two parties meet, the predominant action is for one to walk toward the other in a slow manner. The meaning is: "When you meet the disbelievers, walking to fight them and heading toward battling them—or [meaning] each one of you walking toward his counterpart—then do not turn away." The restriction of the prohibition to this is to clarify what is intended by the meeting and to highlight the abhorrence of turning away, as it contradicts that state; it is as if it were said: "Since you have advanced, do not retreat." In this, there is contemplation.

The meaning of "turning away the backs" is defeat, for the defeated one turns his back to the one who defeated him. The expression turned from "backs" to "adbar" (backsides) to render defeat ugly and to repel from it. It may be said: The verse is like [the prohibition]: "And do not approach adultery," and the meaning—based on the assumption that it is a hal from the object, as is apparent, and considering the numerical superiority in Zahf and its relation to them—is: "O you who have believed, when you meet your disbelieving enemies for battle, while they are a vast multitude and you are a small number, do not turn your backs to them—let alone flee—but rather confront them and fight them despite your small number, and this applies all the more if you were to approach their number or equal them."