Justin Martyr, on Num 21:9

“Moses therefore made a brazen serpent, and set it up for a sign: which when they that were bitten looked upon, they were healed.”

“For tell me, was it not God who commanded by Moses that no image or likeness of anything which was in heaven above or which was on the earth should be made, and yet who caused the brazen serpent to be made by Moses in the wilderness, and set it up for a sign by which those bitten by serpents were saved? Yet is He free from unrighteousness. For by this, as I previously remarked, He proclaimed the mystery, by which He declared that He would break the power of the serpent which occasioned the transgression of Adam, and [would bring] to them that believe on Him [who was foreshadowed] by this sign, i.e., Him who was to be crucified, salvation from the fangs of the serpent, which are wicked deeds, idolatries, and other unrighteous acts.”

Imported from an open dataset — not yet checked against the printed edition.