Charles Ellicott Commentary Numbers 27:17

"who may go out before them, and who may come in before them, and who may lead them out, and who may bring them in; that the congregation of Jehovah be not as sheep which have no shepherd." — Numbers 27:17 (ASV)

Which may go out before them ... — The expression going out and coming in is used here, as in many other places, to denote the ordinary life of man (Deuteronomy 28:6; Deuteronomy 31:2). Leading out and bringing in (literally, causing to go out and to come in), as a shepherd in respect of his flock (John 10:3–9), denotes the direction of the conduct of others.