a man - rather, the man Christ [Lowth]; it is as “the Son of man” He is to reign, as it was as Son of man He suffered (Mat 26:64; Joh 5:27; Joh 19:5). Not as Maurer explains, “every one of the princes shall be,” etc.
rivers - as refreshing as water and the cool shade are to the heated traveler (Isa 35:6, Isa 35:7; Isa 41:18).