Surah al-Inshiqaq is Makkan. (1)
In the name of Allah, the Most Compassionate, the Most Merciful.
“When the heaven is split asunder, and heeds its Lord—as it must—and when the earth is stretched out, casts out what is within it and becomes empty, and heeds its Lord—as it must.”
“when the heaven is split asunder”: Its splitting is among the signs of the Resurrection.
“and heeds its Lord”: that is, it hears its Lord’s command to split apart and obeys Him. This derives from udhun, meaning listening. “as it must”: that is, it is right and fitting for it to obey its Lord.
“and when the earth is stretched out”: like the stretching of Ukazi leather, and its expanse is increased. Muqatil said: “It is levelled like stretched leather, so that no building or mountain remains upon it.”
“and casts out”: it brings forth “what is within it” of the dead and treasures, “and becomes empty”: [is emptied] (2) of them.
“and heeds its Lord—as it must”: The scholars differed concerning the response to “when.” It was said that its response is omitted, its implied meaning being: When these things take place, man will see reward and punishment.
And it was said that its response is: “O man, you are surely striving toward your Lord”; its intended sense is: When the heaven is split asunder, every striving person will encounter what he has done. (3)
And it was said that its response is: “and heeds,” in which case the conjunction “and” is superfluous.