Tafsir of At-Tariq 86:11

"And the heaven" — which is the canopy, according to the majority of scholars — "possessing the raj'" (return), that is, rain, according to them as well. As Al-Khansa says on the day of farewell: "You see tears flowing like the raj' in a heavy, nocturnal raincloud." Its origin is the verbal noun of the transitive and intransitive verb raja'a (to return). Its specific verbal noun is ruju'; they named rain with it just as they named it awb, the verbal noun of aba. From this is the saying: "A lofty, high mountain peak that none take refuge in except the clouds and the awb (rain) and the heavy downpours." [It is called raj'] either because it returns, or because the clouds carry it from the seas of the earth then return it to the earth. Many have built this upon conjecture, and there is room for debate in it.

It is narrated from Ibn Abbas and Mujahid that it is interpreted as the clouds, and raj' as the rain.

It is said that what is meant by it is the bees, because Allah, the Exalted, returns them [to their hives] from time to time. Al-Hasan said: "Because it returns with sustenance every year," or they intended by that optimism.

Ibn Zayd said: The heaven is the well-known one, and raj' is the return of the sun, the moon, and the planets from one state to another, and from one station to another within it.

It is said [it refers to] their returning themselves, for in every cycle they return to the position from which they move. This is built upon the premise that the heaven and the celestial sphere are one and the same; thus, it moves, and its apogee becomes its perigee, and its perigee becomes its apogee. You have already heard previously that the apparent meaning of the speech of the predecessors is that the heaven is distinct from the celestial sphere, and that it neither rotates nor moves. What was just mentioned is the opinion of the philosophers and those who followed them.

It is said that raj' refers to the angels (peace be upon them); they are named as such due to their returning with the deeds of the servants.