So the lightning seized them on account of their injustice.
"And We raised the (Sinai) Mount above them at (the taking of) their covenant and We said to them: 'Enter the door prostrating', and We said to them: 'Do not transgress the Sabbath!' and We took from them a firm covenant." The verse implies that the Children of Israel, the Jews, did not awaken from the sleep of negligence and did not come down from the mount of pride and obstinacy.
It was for that reason that Allah raised the Sinai Mount above them, and in the meanwhile, He took covenant from them. "And We raised the (Sinai) Mount above them at (the taking of) their covenant…" The holy verse implies that Allah (s.w.t.) told them to enter the door of Jerusalem in the state of prostration and humility as a sign of repentance from their sins.
Allah also decreed emphatically for them not to work on Saturday and not to transgress, (and not to use the sea-fish that the hunting of which was prohibited for them). Allah (s. w.t.) took serious covenant for all of these things from them. But they fulfilled none of those confirmed promises.
"So, for their breaking their covenant and their disbelief in the Signs of Allah and their slaying the prophets wrongfully and their saying: 'Our hearts are covered', nay! but Allah sealed them for their disbelief, so they do not believe save a few. " In this verse, the Qur'an points to some other parts of the wrong doings of the Children of Israel, and also those committing offences and hostilities that the Jews performed against the prophets of Allah.
At first, it refers to the breach of promise and disbelief of a group of them, by whom the slaughter of many prophets occurred.