TSK
مراجع Treasury of Scripture Knowledge في ASV.
And I, behold, I have taken the Levites from among the children of Israel instead of all the first-born that openeth the womb among the children of Israel; and the Levites shall be mine:
from thirty years old and upward even until fifty years old, all that enter upon the service, to do the work in the tent of meeting.
And thou shalt set the Levites before Aaron, and before his sons, and offer them for a wave-offering unto Jehovah.
Moreover David and the captains of the host set apart for the service certain of the sons of Asaph, and of Heman, and of Jeduthun, who should prophesy with harps, with psalteries, and with cymbals: and the number of them that did the work according to their service was: