5 Or shall we take another favorite passage of yours: "They shall see their life hanging, and shall not believe their life?" You insert the words "on a tree," which are not in the original. Nothing can be easier than to show that this has no reference to Christ. Moses is uttering dire threatenings in case the people should depart from his law, and says among other things that they would be taken captive by their enemies, and would be expecting death day and night, having no confidence in the life allowed them by their conquerors, so that their life would hang in uncertainty from fear of impending danger.
This passage will not do, we must try others. I cannot admit that the words, "Cursed is every one that hangs on a tree," refer to Christ, or when it is said that the prince or prophet must be killed who should try to turn away the people from their God, or should break any of the commandments. That Christ did this I am obliged to grant. But if you assert that these things were written of Christ, it may be asked in reply, What spirit dictated these prophecies in which Moses curses Christ and orders him to be killed?
If he had the Spirit of God, these things are not written of Christ; if they are written of Christ, he had not the Spirit of God. The Spirit of God would not curse Christ, or order Him to be killed. To vindicate Moses, you must confess that these passages too have no reference to Christ. So, if you have no others to show, there are none. If there are none, Christ could not have said that there were; and if Christ did not say so, that verse is spurious.
Source: Reply to Faustus the Manichaean (New Advent)