Tafsir of An-Nahl 16:37

Then He mentioned the obstinacy of Quraysh and the Messenger of Allah’s (ﷺ) eagerness for their faith. He informed him that they belong to the category of those upon whom misguidance has been decreed, and that "He does not guide those whom He leads astray"—meaning: He does not grant grace to those whom He abandons, for that would be futile, and Allah Almighty is exalted above futility, as it is among the reprehensible acts that are not permissible for Him.

It is read: "He is not guided" (lā yuhdā), meaning: neither you nor anyone else is capable of guiding one whom Allah has abandoned.

His saying: "And they have no helpers" is evidence that the intended meaning of "leading astray" (iḍlāl) is abandonment (khidhlān), which is the opposite of providing aid.

It is permissible for "He is not guided" (lā yuhdā) to mean "he does not accept guidance" (lā yahtadī). It is said: "Allah guided him, so he accepted guidance" (hadāhu Allāhu fahadā).

In the reading of Ubayy: "For indeed Allah does not guide those whom He leads astray, and those whom He has led astray," which supports those who read lā yuhdā in the passive voice.

In the reading of ‘Abd Allāh: "He is guided" (yaddī), by assimilating the tā’ of yahtadī, which supports the first [active] reading.

It is read: yuḍill (with a fatḥah on the yā’).

Al-Nakha‘ī read: in taḥraṣ (with a fatḥah on the rā’), which is a dialectal variant.