פירוש על במדבר 21:7

ויתפלל משה AND MOSES PRAYED — From this we may learn that he of whom one seeks forgiveness should not be so cruel as not to forgive (cf. Midrash Tanchuma, Chukat 19).

התפלל אל השם, "pray to the merciful G'd, etc." In this instance the meaning of the word התפלל is equivalent to a call for forgiveness of the sin. There is a difference in the accessibility of forgiveness if one prays for it before the guilty party has experienced afflictions or if one has waited until after he has experienced afflictions. Once the guilty party has already become the victim of the destructive forces he himself has created and which have come home to roost, he needs to marshall some merit in order for these destructive forces to be called off. Shabbat 32 has this to say on the subject: "A person should make a point of asking for mercy before he falls sick because once he has fallen sick they say to him: 'produce some merit and you will be freed from the sickness.'" This is why the people of the generation of the desert (also known as the דור דעה, the generation blessed with knowledge) were astute enough to ask Moses to pray before asking him to remove the destructive serpents. They wanted Moses to invoke his own merits on their behalf.

הנחש, a collective term meaning many of them.

ויאמרו חטאנו כי דברנו בה' ובך, “they said: ‘we have sinned in that we spoke out against G’d and against you.’” They asked forgiveness from Moses and admitted their guilt. Moses then prayed on their behalf as it says: “Moses prayed on behalf of the people” (verse 7). This episode teaches that if someone asks a person’s forgiveness for insults committed against him the injured party should not be cruel and refuse to accept the apology (compare Tanchuma Chukat 19). We find, for instance that Avraham prayed on behalf of Avimelech who had wronged both him and Sarah (Genesis 20,17); also Job had prayed on behalf of his friends (Job 42,10). If someone refuses to pray on behalf of his fellow when called upon to do so he is called “a sinner.” Samuel explained this to the people when he explained to them why he was prepared to pray on their behalf (Samuel I 12,23).

את הנחש, “the snake;” sometimes the word נחש appears in the singular, and sometimes in the plural mode. This is not unique, as we experienced it with the frogs in Exodus 8,2, also.

ויסר מעלינו את הנחש “so that He will remove the snake (plague of) from us.” Actually, we would have expected the word הנחשים, “the snakes” (pl.), instead of the word הנחש, “snake” (sing.). The reason the Torah uses the singular is to allude to the lethal power of the snake, serpent, mentioned earlier. The Torah refers to the spiritual representative of the snakes whose residence is in the desert. When the Jewish people said מעלינו, instead of ממנו, they meant “the one who is above us,” instead of merely “away from us.” We find a similar expression in Numbers 14,9 where Calev described that the protective force of the Canaanites had already been withdrawn from them as: סר צלם מעליהם, “their protective shadow has departed from above them.” This will also enable you to understand a verse in Zecharyah 6,1 וההרים הרי נחשת, “and the mountains are mountains made of copper” [a comment which appears irrelevant at first glance. Ed.]. The word נחשת is understood as derived from השחתה, “destruction.” Although the mountains mentioned by the prophet are destructible, the four chariots representing the glory of the Lord mentioned in that same verse are indestructible (based on Maimonides Moreh Nevuchim section two 10th chapter). It is a reference to the “great mountain” which features in the vision of Zerubabel as an insurmountable obstacle but which G’d promises will be reduced to level ground (vision of Yehoshua High Priest, Zecharyah 4,7)

את הנחש, the serpent. They wanted that G'd should remove even the relatively minor problem, the deadly bite of the snake that attacked only the bodies. If they had mentioned the שרף or the נחש השרף it would have sounded as if they were only concerned about not having their souls destroyed but would have been content to die a merely physical death, i.e. a normal death. By mentioning only the נחש, the people made it plain that they did not want to die a natural death of the body, and if so, they certainly did not want their souls to die. They were also careful to speak of the נחש in the singular to indicate that they did not want a single snake to remain.