Slay thou not,.... Though they deserved to be slain, and the Lord seemed as if he was about to slay them, who was able to do it; he seemed to be whetting his glittering sword, and his hand to take hold of vengeance ready to execute it; wherefore intercession is made to spare them, which agrees with Christ's petition on the cross, Lu 23:34.
The Targum adds, "immediately": slay them not directly, and at once; give them space for repentance; and so the Jews had: for it was forty years after the death of Christ before their destruction was: or the meaning may be, slay them not utterly; destroy them not totally: and so it was; for though multitudes were slain during the siege of Jerusalem, and at the taking of it, yet they were not all slain: there were many carried captive, and sent into different parts of the world, whose posterity continue to this day.
The reason of this petition is,lest my people forget: the Syriac version renders it, "lest they should forget my people"; or my people should be forgotten. David's people, the Jews by birth and religion, though not as yet his subjects, unless in designation and appointment, and Christ's people according to the flesh: now if these had all been slain at once, they had been forgotten, like dead men out of mind: or Christ's special and peculiar people; his chosen, redeemed, and called ones, who truly believe in him, and are real Christians; and then the sense is, if full vengeance had been taken of the Jews at once, and they had been cut off root and branch, so that none of them remained, Christ's people would have forgot them, and the vengeance inflicted on them for their rejection of the Messiah; but now they are a continued and lasting instance of God's wrath and displeasure on that account, and they and their case cannot be forgotten.
The Arabic version renders it, "lest my people forget the law"; its precepts and sanction, its rewards and punishments;scatter them by thy power; or let them wander up and down like fugitives and vagabonds in the earth, as Cain did, and as the Jews now do, being dispersed in the several parts of the world; and which was done by the power of God, or through the kingdom of God coming with power upon that people, Mr 9:1; or "by thine army" ; the Roman army, which was the Lord's, being permitted by him to come against them, and being made use of as an instrument to destroy and scatter them, Mt 22:7;and bring them down; from their excellency, greatness, riches, and honour, into a low, base, mean, and poor estate and condition, in which the Jews now are;O Lord, our shield; the protector and defender of his people, while he is the destroyer and scatterer of their enemies.