al-Naḥl 16:79

A-lam yaraw ila'l-ṭayri musakhkharātin fī jawwi'l-samāʾ, mā yumsikuhunna illa'llāh, inna fī dhālika la-āyātin li-qawmin yuʾminūn

"Have they not seen the birds, made subservient in the open air of the sky? None holds them up but God. In that there are signs for a people who believe."

The word occurs only here in the Qurʾān. Its sense: the open space between earth and sky. The lexicographers describe jaww as "a wide space that is empty within".

And the construction must be recorded: fī jawwi'l-samāʾ — "in the open of the sky". The verse names the place where the bird flies an emptiness — the place where there is nothing to take hold of.

I give this as my own reading, its ground being the choice of word: the rest of the sentence is mā yumsikuhunna illa'llāh — "none holds them up but God." The word prepares the sentence's verb in advance: where there is nothing to take hold of, one asks who is holding.

The root of imsāk (holding) was the backbone of Fāṭir — it was tabulated there that at 35/2 (fa-lā mumsika lahā) and at 35/41 (inna'llāha yumsiku'l-samāwāti wa'l-arḍa an tazūlā) it bound the two ends of that sūra together. I rely on that treatment.

Three verses can be set side by side:

The difference of scale must be recorded, and I give it as an observation: Fāṭir tells of the hand that holds the universe; al-Naḥl uses the same verb of a bird. This suits the sūra's logic of enumeration: the evidence is chosen from close at hand.

And the same scene occurs at al-Mulk, 67/19 (a-wa-lam yaraw ila'l-ṭayri fawqahum ṣāffātin wa yaqbiḍna, mā yumsikuhunna illa'l-raḥmān) and was treated there. The two verses are almost identical, and the difference lies in a single word:

This is an overlap verifiable across the sūras. And the difference is worth recording: al-Mulk describes the bird's motion (the spreading and folding); al-Naḥl its condition (made subservient). al-Naḥl's word (musakhkharāt) is the very word used of the stars in the twelfth verse. This is a repetition verifiable within the sūra.