Ibn Abbas and Qatadah said: That is, “We decreed against them”; the preposition “to” here carries the meaning of “against,” and “the Book” means the Preserved Tablet.
“You will surely spread corruption”: the particle is the lām of oath; its sense is, “By Allah, you will surely spread corruption”—“in the land twice,” through acts of disobedience. What is meant by “the land” is the land of Syria and Jerusalem. “And you will surely rise in great transgression”: that is, you will act arrogantly and wrong people greatly.
“So when the time of the first of the two promises came, We sent against you servants of Ours, possessors of great might, and they penetrated the midst of your homes. And it was a promise bound to be fulfilled. (5) Then We gave you your turn to prevail over them, and reinforced you with wealth and sons, and made you more numerous in forces. (6) If you do good, you do good for your own souls; and if you do evil, it is against them. Then, when the time of the latter promise came, [We sent them] to disgrace you, to enter the Sanctuary as they entered it the first time, and to destroy utterly whatever they conquered. (7)”
“So when the time of the first of the two promises came”: that is, the first of the two occasions.
Qatadah said: Their corruption on the first occasion consisted in their violating the rulings of the Torah and committing forbidden acts.
Ibn Ishaq said: Their corruption on the first occasion was their killing Isaiah within the tree, as well as their committing acts of disobedience.
“We sent against you servants of Ours.” Qatadah said: This refers to Goliath the Khazar and his troops—the one whom David killed.
Sa‘id ibn Jubayr said: It refers to Sennacherib, one of the people of Nineveh.
Ibn Ishaq said: Nebuchadnezzar of Babylon and his companions. This is the more apparent view.
“Possessors of great might”: that is, men of great force; “great,” in war. “And they penetrated”: that is, they went about and roamed “amid the homes,” searching for you and killing you. To penetrate in this sense is to seek something out thoroughly. Al-Farra’ said: They killed you among your houses.
“And it was a promise bound to be fulfilled”: a decree certain to come to pass, with no failure in it. “Then We gave you your turn”: that is, the return of power and dominion “over them; and We reinforced you with wealth and sons, and made you more numerous in forces”—that is, in numbers, namely those who would go forth with them. The land was restored in a better state than it had been.
“If you do good, you do good for your own souls”: that is, they receive its reward. “And if you do evil, it is against them”: that is, against them, just as in His saying, “So peace be upon you” (al-Waqi‘ah, 91)—that is, upon you. It was also said: they will bear its requital and punishment.