Commentary for Numbers 24:4

נפל וגלוי עינים FALLING BUT HAVING HIS EYES OPEN — Its plain sense is as the Targum has it (“lying down when it was revealed to him”), meaning, that God revealed Himself to him only at night when he was lying on his bed. — And a Midrashic explanation of it is: When He revealed Himself to him he had no strength to stand on his feet, and he, therefore, fell on his face — because he was uncircumcised and it was therefore a loathsome thing that He should reveal Himself to him whilst he stood in an erect posture before Him (cf. Tar. Jon. and Rashi on Genesis 17:3).

אשר מחזה שדי יחזה, sometimes, when he was asleep in bed, and sometimes with his eyes open, i.e. גלוי עיניפ in daytime. At the time he was speaking these lines he was granted prophetic vision in full daylight. The word נופל means that the subject had no control over his body, compare Samuel I 31,8.

שומע אמרי א-ל, “the one who has first-hand experience in hearing G’d’s words.” This was another way of declaring himself as a prophet.