“And return to your Lord and submit to Him.”

And return in repentance to your Lord and submit to Him before the punishment comes upon you; then you will not be helped.

This is the verse that follows the promise that Allah forgives all sins, and it is the condition attached to it. The two things asked for are turning back and submitting — and then a limit is named: before the punishment comes, after which no help arrives. Read together, the pair says the door is wide open and that it does not stay open indefinitely.