מַלְאָ֣ךְ רָ֭שָׁע יִפֹּ֣ל בְּרָ֑ע וְצִ֖יר אֱמוּנִ֣ים מַרְפֵּֽא׃
El mal mensajero caerá en mal: Mas el mensajero fiel es medicina.
Rashi on Proverbs
A wicked messenger falls into evil like Balaam, to whom the Holy One, blessed be He, said (Num. 22:35): “Go with the men,” but he dealt wickedly to entice Balak to follow his evil counsel; therefore, he fell by the sword.
Rashi on Proverbs
but a faithful emissary brings healing This is Moses, our teacher.