Rashi on Numbers 11:31/רש"י על במדבר י״א:ל״א

1ויגז means “and he caused to fly”; similar is, (Psalms 90:10) “for it flies away (גז)”; so, also, (Nahum 1:12) “they shall fly off (נגוזו) and it shall pass away”.

2ויטש means “and he spread them abroad” (while flying), as (I Samuel 30:16) “and behold, they were spread abroad (נטושים) upon all the earth”; (Ezekiel 29:5) “and I have spread thee about (ונטשתיך) the wilderness”.

3וכאמתים AND ABOUT TWO CUBITS [HIGH UPON THE FACE OF THE EARTH] — This means that they were flying at a height (of two cubits from the ground) so that they reached just up to a man’s breast, in order that there should be no trouble in gathering them, either to stretch upwards or to bend down to pick them up (Sifrei Bamidbar 97).