Mustafa Khattab:Translation:
When you ˹O Prophet˺ are ˹campaigning˺ with them and you lead them in prayer, let one group of them pray with you—while armed. When they prostrate themselves, let the other group stand guard behind them. Then the group that has not yet prayed will then join you in prayer—and let them be vigilant and armed.32 The disbelievers would wish to see you neglect your weapons and belongings, so they could launch a sweeping assault on you. But there is no blame if you lay aside your weapons when overcome by heavy rain or illness—but take precaution. Indeed, Allah has prepared a humiliating punishment for the disbelievers.

A. Yusuf Ali:Translation:
When you (O Messenger. are with them, and
standest to lead them in prayer, Let one party of them
stand up (in prayer) with you, Taking their arms with
them: When they finish their prostrations, let them
Take their position in the rear. And let the other party
come up which have not yet prayed - and let them
pray with you, Taking all precaution, and bearing
arms: the Unbelievers wish, if you were negligent of
your arms and your baggage, to assault you in a single
rush. 618 But there is no blame on you if you put away
your arms because of the inconvenience of rain or
because you are ill; but take (every) precaution for
yourselves. For the Unbelievers Allah have prepared a
humiliating punishment.

Muhammad Asad:Translation:
Thus, when thou art among the believers 129 and about to lead them in prayer, let [only] part of them stand up with thee, retaining their arms. Then, after they have finished their prayer, let them provide you cover 130 while another group, who have not yet prayed, shall come forward and pray with thee, being fully prepared against danger and retaining their arms: (for) those who are bent on denying the truth would love to see you oblivious of your arms and your equipment, so that they might fall upon you in a surprise attack. 131 But it shall not be wrong for you to lay down your arms [while you pray] if you are troubled by rain 132 or if you are ill; but [always] be fully prepared against danger. Verily, God has readied shameful suffering for all who deny the truth!
32 When the first group prays, the second group stands guard behind them, then the first group withdraws to the back when they finish their prayers and stand guard when the second group moves up to pray.