وَأَنَّا ظَنَنَّا أَن لَّن نُّعْجِزَ اللَّهَ فِي الْأَرْضِ وَلَن نُّعْجِزَهُ هَرَبًا
"And that: we came to understand that we can never frustrate God on the earth, nor frustrate Him by fleeing."
The verb occurs for the third and last time in the sūra. In verses 5 and 7 the suppositions turned out false; here the supposition is true.
And note its subject: the one supposition that turned out true is the one about their own powerlessness.
This is no accidental arrangement. The sūra lines up three suppositions, two of them about God (nobody lies about Him / He will raise no one), one about themselves (we cannot escape Him). The false ones are those that assume too much about God; the true one is the one that assumes little about oneself.
Rendering it "we came to understand" fits here; for in this context the verb conveys arriving at a firm conviction.
Root ع-ج-ز. And the concrete sense of the root lies in an unexpected place: عَجُز (ʿajuz) is the hind part, the rear of a thing. The rear section of a camel, the end of something.
From here the notion of ʿajz derives, and the logic of the derivation is this: to remain at the back / at the end of a matter — that is, not to catch up, to be left behind, to be unable. The English "to fall behind" carries a similar logic.
The pattern matters: nuʿjiza — the ifʿāl form (aʿjaza), causative. Not "to be unable" but "to render unable". That is, to pass into a position someone's power cannot reach.
The Qurʾān uses this pattern regularly in the context of the impossibility of fleeing from God: "You will not frustrate on the earth" (al-ʿAnkabūt 29/22, and like expressions occur in several places). From the same root comes the word muʿjiza: what renders the one facing it unable.
- lan nuʿjiza'llāha fi'l-arḍ — "we cannot frustrate Him on the earth"
- wa lan nuʿjizahu harabā — "nor can we frustrate Him by fleeing"
The first door: resistance. To stand where you are and oppose. The expression "on the earth" states place: within the field we live in, where we are.
Two options, which cover everything a human being (and here the jinn) can do in the face of a power: stay and resist, or go. The verse closes both.
The grammatical position of the word هَرَبًا has been dwelt on. It is a verbal noun (harab — to flee) and can be analysed in the sentence in several ways: as a circumstantial ("fleeing"), or with a function resembling an object of purpose ("by fleeing"). It makes no serious difference to the sense; in either case fleeing stands as the method of the attempt to frustrate.
This idea is expressed in the Qurʾān with a plain sentence of challenge as well, and its addressees are again jinn and human beings:
"O company of jinn and human beings! If you can pass beyond the bounds of the heavens and the earth, then pass. You will not pass save by an authority." (al-Raḥmān 55/33)
The same two kinds, the same matter: the attempt to go outside the field. Al-Jinn 72/12 is like the answer to that challenge — the jinn have given the answer on their own behalf: we cannot pass.
In verse 6 human beings were seeking refuge with the jinn. Here the jinn say of themselves "we cannot escape."
The party sought refuge with confesses that it has nowhere to flee. The meaning of seeking refuge is to pass into a place where what is feared cannot reach. The jinn say they have no such place. Whoever seeks refuge with them, therefore, has hidden behind someone who has nowhere to flee.
Nowhere does the sūra make this finding plainly. It places the two verses in the same list and expects the reader to make the connection.
And the same structure will be repeated in verse 22 with the highest example: "Say: no one can save me from God, and I shall find no refuge apart from Him." The Prophet, that is, frames the same sentence about himself. The sūra completes from the bottom upward the list of beings that cannot be a refuge: the jinn cannot escape — nor can the messenger be saved.