And Moses chose seventy men from his people for meeting with Us; thus, when a violent trembling seized them, he said: "My Lord! If You had wished, You could have destroyed them and me before, are You destroying us for what the fools among us had done? Indeed, It is nothing except Your trial, You let stray with it whomever You wish, and You let guide whomever You wish, You are our Patron, so You forgive to us and You show Mercy upon us; indeed, You are the Best among the forgivers".
The children of Israel told Moses that they will never believe in him until they see the Lord manifestly as explained in verse 2: 55. So Moses chose seventy representatives from them and went to Mount Sinai. Then they were seized with a thunderbolt and they fainted. When they got consciousness, Moses prayed by the soul as told in this verse.
Whomever holdfasts Adhikr which is the Best Interpretation of the Lord's Book, he did holdfast and is guided into the Straightpath as explained in verse 5: 48. Whoever hides and rejects Adhikr after receiving It, such are strayed and are serving Satan and are hurrying for the Antichrist as well as Doomsday as explained in verse 6: 158. See the explanation 2: 28; 3: 58; 5: 78-81, and 6: 25-26.