Tafsir of Al-Jinn 72:16-17

{And if they had remained straight} The an (that) is the lightened form of the heavy anna. It is part of what was revealed. The meaning is: It was revealed to me that the matter and the discourse is that if the Jinn had remained straight upon the ideal path—meaning, if their forefather, the Jinn, had remained firm upon what he was upon regarding the worship of Allah and obedience, and had not grown arrogant regarding prostrating to Adam, and had not disbelieved, and his offspring had followed him in Islam—{We would have given them abundant water to drink}.

The "abundant water" (al-ghadaq)—which means plentiful, and is read with both a fatha and a kasra on the dal—is mentioned because it is the foundation of livelihood and the expansion of provision.

{That We might test them therein} To test them through it: how they show gratitude for what they have been granted of it.

It is also possible that the meaning is: If the Jinn who listened had remained upon the path they were on before listening, and had not transitioned to Islam, We would have expanded their provision to lead them on by degrees (istidraj), to tempt them therein. This is so that the blessing becomes a cause for them to follow their desires, fall into temptation, and increase in sin; or so that We may punish them for their ingratitude for the blessing.

{From the remembrance of his Lord} Meaning: from His worship, His admonition, or His revelation.

{He will cause him to enter} Read with both a damma and a fatha on the nun (naslukuhu / nuslikuhu), meaning: We will cause him to enter. The original structure is "We will cause him to enter into a punishment," like His saying: "What has caused you to enter Saqar?" (Al-Muddaththir: 42). It is made transitive to two objects either by omitting the preposition and connecting the verb directly—like His saying: "And Moses chose from his people" (Al-A'raf: 155)—or by implying the meaning of "We will cause him to enter." It is said: salakahu and aslakahu. A poet said: "Until they caused them to enter into thorny branches."

{A severe punishment} Al-sa'ud is the verbal noun of sa'ada. It is said: sa'ada sa'adan wa su'udan. It is used to describe the punishment because it overcomes the one being punished—meaning it rises above him and defeats him, such that he cannot bear it. From this is the saying of Umar (may Allah be pleased with him): "Nothing has ever been as difficult for me (ma tasa'adani) as the marriage sermon," meaning: nothing has been as hard for me or defeated me as much.

{And the mosques are for Allah, so do not call upon anyone with Allah}