"And Moses made a copper snake." (Num. 21:9)

The Tzror Hamor, in his commentary on parashat Bo, in connection with the mezuzot and mashkof (lintel), describes how jealous G‑d was of the honor of the righteous, more so even than of His own honor. This is why the word mezuzot, plural thus corresponding to Moses and Aaron, is mentioned first, whereas the word "mashkof " (which is above the mezuzot), corresponding to G‑d, is mentioned last. Moses was unwilling to have that which symbolized G‑d mentioned last; therefore when relaying the command, he mentioned the word mashkof first. (Compare G‑d's commandment to Moses (Ex. 13:7) and where Moses relays these instructions to Israel (Ex. 12:22)). We must be careful not to besmirch the honor of Torah scholars…

We have a similar situation here. (Num. 21:5-9) The people spoke up against G‑d and against Moses and G‑d dispatched serpents and venomous snakes against them. He sent the serpents because they had spoken out against G‑d and the venomous snakes because of their having criticized Moses, who is compared to an angel of the seraph variety; in Hebrew "seraph" also means serpent. Therefore, after the people repented, G‑d told Moses to make a "seraph" for himself and put it on a pole, etc. Moses however, did not make a seraph; he rather made a snake, seeing that he considered restoring G‑d's honor as more important than restoring his own honor, even though a seraph was what G‑d had instructed him to make. From all this we learn to what extent we must be careful not to besmirch the honor of Torah scholars, righteous people, etc.

[Translation and commentary by Eliyahu Munk.]