وَيَصلىٰ سَعيرًا

And he will enter the blaze.

EXEGESIS

Yaṣlā (he will enter) is from the verb ṣalā-yaṣlī, which, in this context, means to be persistently in company of something or entering into it.^{‎[1]Mizan, 20/227.} Also, ṣaly in this context means to be placed in or by fire for burning, cooking, or heating up.^{‎[2]Tibyan, 3/126.} Taṣliyatu jaḥīm (56:94) means making to enter fire to be burnt.

Saʿīr (the blaze) means the blazing fire,^{‎[3]Raghib, p. 411, s-ʿ-r.} specifically when it is accompanied by an intense heat, like in the verse, Their refuge shall be hell. Whenever it subsides, We shall intensify the blaze (saʿīr) for them (17:97).^{‎[4]Tahqiq, 5/158, s-ʿ-r.} The price of something is called siʿr, because the prices in the market fluctuate and rise up like the flame of a fire.^{‎[5]Bahrayn, 3/331, s-ʿ-r.}

The Arabic saʿīran is indefinite (lit. a blaze), but has been translated with the definite article as the blaze for stylistic reasons.

[1] Mizan, 20/227.
[2] Tibyan, 3/126.
[3] Raghib, p. 411, s-ʿ-r.
[4] Tahqiq, 5/158, s-ʿ-r.
[5] Bahrayn, 3/331, s-ʿ-r.