The word(s) "let" appears 320 time(s) in 279 verse(s) in Quran in Muhammad Pickthal translation.

(21) let not the believers take disbelievers for their friends in preference to believers. Whoso doeth that hath no connection with Allah unless (it be) that ye but guard yourselves against them, taking (as it were) security. Allah biddeth you beware (only) of Himself. Unto Allah is the journeying.

(22) Nay, but (the chosen of Allah is) he who fulfilleth his pledge and wardeth off (evil); for lo! Allah loveth those who ward off (evil).

(23) Wherein are plain memorials (of Allah's guidance); the place where Abraham stood up to pray; and whosoever entereth it is safe. And pilgrimage to the House is a duty unto Allah for mankind, for him who can find a way thither. As for him who disbelieveth, (let him know that) lo! Allah is Independent of (all) creatures.

(24) These are revelations of Allah. We recite them unto thee in truth. Allah willeth no injustice to (His) creatures.

(25) When two parties of you almost fell away, and Allah was their Protecting Friend. In Allah let believers put their trust.

(26) If Allah is your helper none can overcome you, and if He withdraw His help from you, who is there who can help you after Him? In Allah let believers put their trust.

(27) It is not for any prophet to embezzle. Whoso embezzleth will bring what he embezzled with him on the Day of Resurrection. Then every soul will be paid in full what it hath earned; and they will not be wronged.

(28) let not their conduct grieve thee, who run easily to disbelief, for lo! they injure Allah not at all. It is Allah's Will to assign them no portion in the Hereafter, and theirs will be an awful doom.

(29) And let not those who disbelieve imagine that the rein We give them bodeth good unto their souls. We only give them rein that they may grow in sinfulness. And theirs will be a shameful doom.

(30) It is not (the purpose) of Allah to leave you in your present state till He shall separate the wicked from the good. And it is not (the purpose of) Allah to let you know the Unseen. But Allah chooseth of His messengers whom He will, (to receive knowledge thereof). So believe in Allah and His messengers. If ye believe and ward off (evil), yours will be a vast reward.