tn The verb is the Piel perfect of שָׁרַת (sharat, “to serve, minister”). Here the form has the vav (ו) consecutive, and so is equal to the imperfect tense stressing permission. After the Levites reached the age of retirement, they were permitted to assist the others, but were not permitted to do the work themselves.
tn Heb “brothers,” but the meaning in this context is “fellow Levites.”
tn Heb “you shall do, make.”