That you may settle yourselves upon their backs and then remember the favor of your Lord when you have settled upon them and say, "Exalted is He who has subjected this to us, and we could not have [otherwise] subdued it.
Sahih International
لِتَسْتَوُۥا۟
litastawū
That you may sit firmly
Word breakdown
ل
Harf · Purpose particleso that
تسْتوُ
Fi'l · VerbThat you may sit firmly
to make equal, fashion proportionately, establish
83× in the Quran · Occasional
ا
Ism · Personal pronounyou all/your
Grammar rules
لِتَسْتَوُۥا۟ (That you may sit firmly) is in the subjunctive mood — it comes after a particle like أن ("that") or لن ("will not"), which changes its ending.
We translate it as "to [verb]" or "that [someone] [verb]".
Lesson 10 · Commands & Futureلِتَسْتَوُۥا۟ (That you may sit firmly) uses form VIII (إِفْتَعَلَ) — it means doing the action for yourself or by yourself.
We translate it as "to [verb] for oneself".
Lesson 13 · Verb Families V–Xلِتَسْتَوُۥا۟ (That you may sit firmly) starts with لِ showing purpose — it means "so that" or "in order to".
We add "so that" or "in order to" before the verb.
Lesson 4 · Particles