Rashi on Numbers 20:16/רש"י על במדבר כ׳:ט״ז

1וישמע קלנו HE HEARD OUR VOICE — through the blessing with which our father, Jacob, had blessed us — “the voice is Jacob’s voice” (Genesis 27:22), because whenever we cry we are answered (Midrash Tanchuma, Beshalach 9 on בשלח).

2מלאך A MESSENGER (or an angel) — This was Moses; from this we may learn that the prophets are termed “angel”; so, too, it says, (II Chronicles 36:16) “And they grieved the angels (מלאכי) of God” (Leviticus Rabbah 1:1).