Sforno on Numbers 4:49/ספורנו על במדבר ד׳:מ״ט

1EACH ONE TO HIS WORK AND HIS PORTERAGE AND HIS RESPONSIBILITY. He appointed each one to the work that he would do at the time of encampment AND HIS PORTERAGE at the time of traveling, that he would know the weight of his burden and he would know his responsibility, i.e., that he would know the names of the names of the items that he would carry that were designated by name, as it is said (v.32), "you shall list by name the objects that are their porterage tasks."