en_tn_condensed/num/04/49.md

At Yahweh's command

"As Yahweh commanded"

keeping count of each by the type ... He counted each man by the kind of responsibility he would bear

These two phrase have similar meaning and are used together to emphasize how Moses counted all the men.

by the type of work he was assigned to do

"by his type of work assignment" or "by the type of work he had assigned each man to do"

he would bear

"he would have"

they obeyed what Yahweh had commanded them

Here "they" and "them" refer to Moses and Aaron.