Tafsir of Al-Mulk 67:16-19

{Have you felt secure [from Him] who is in the heaven...} There are two interpretations regarding "who is in the heaven":

1. His dominion is in the heaven: Because it is the dwelling place of His angels, the location of His Throne (‘Arsh), His Footstool (Kursi), and the Preserved Tablet (al-Lawh al-Mahfuz). From there, His decrees, scriptures, commands, and prohibitions descend.
2. Addressing their belief: They held anthropomorphic beliefs, thinking He is physically in the heaven, that mercy and punishment descend from there, and they would pray toward that direction. Thus, it was said to them according to their own belief: "Do you feel secure—from the One you claim is in the heaven, while He is exalted above [being contained by] space—that He will not punish you with a sinking of the earth or a rain of stones?" This is like saying to an anthropomorphist who is committing a sin: "Do you not fear the One above the Throne that He might punish you for what you are doing?"

{Then you will know} It is recited with both the ta (you will know) and the ya (they will know). It means: when you see the thing you were warned about, you will know the nature of My warning, at a time when such knowledge will no longer benefit you.

{Spreading their wings} (saffat) They extend their wings in the air when flying, for when they spread them, they align their primary feathers in a row.

{And they close them} (yaqbidna) They fold them inward when they strike their sides with them.

If you ask: Why is it said "and they close them" (yaqbidna - verb) instead of "and closing them" (qabidat - noun/participle)? I reply: Because the fundamental state of flight is the spreading of wings, just as swimming in water is fundamentally the extension of limbs. Closing the wings is an incidental action that follows the spreading to assist in movement. Therefore, the incidental action is expressed as a verb, implying that they are [primarily] spreaders of wings, and from them, the closing occurs occasionally, just as it does for a swimmer.

{None holds them [aloft] except the Most Merciful} By His power, and by the arrangement He designed for them regarding their primary and secondary feathers, and by constructing their bodies with shapes and characteristics that enable them to glide through the air.

{Indeed He is, of all things, Seeing} He knows how He creates and how He manages wonders.

{Or who is it that could be an army for you to aid you other than the Most Merciful? The disbelievers are not but in delusion. Or who is it that could provide for you if He withheld His provision? But they have persisted in insolence and aversion.}