years they shall return from the service of the work," we know that Levites were disqualified by age. One might have argued that they were disqualified by bodily blemish too; thus, if priests who were not disqualified by age were nevertheless disqualified by bodily blemish, Levites who were disqualified by age should surely have been disqualified by bodily blemish. therefore says: "This is that which pertains to the Levites," to instruct that "this", that is, age, only disqualifies Levites, but nothing else disqualifies them. One might also have argued that priests were disqualified by age too; thus, if Levites who were not disqualified by bodily blemish were nevertheless disqualified by age, priests who were disqualified by bodily blemish should surely have been disqualified by age. therefore says: "Which pertains to the Levites", and not "to the priests". One might further have supposed that the rule that Levites were disqualified by age obtained even at Shiloh and at the Temple at Jerusalem, where the Levites sang in the choir and guarded the doors of the Temple. therefore says: "To do the work of service and the work of bearing burdens," to instruct that God ordained this rule disqualifying Levites by age only when the work was that of bearing burdens upon the shoulder, the service of the Tabernacle in the wilderness, and not at the Temple at Jerusalem. Similarly, the Sifre taught that years invalidated in the case of Levites but not in the case of the priesthood. For prior to the entry into the Land of Israel, the Levites were valid from the age of 30 to the age of 50, while the priests were valid from puberty until the end of their lives. But once they came into the Land, the Levites were invalidated only by losing their voice. Elsewhere, the Sifre read , "and shall serve no more; but shall minister with their brethren in the tent of meeting, to keep the charge, but they shall do no manner of service," to teach that the Levite went back to the work of locking the doors and carrying out the tasks assigned to the sons of Gershom. Rabbi said that a priest with a blemish within the meaning of who officiated at services in the Sanctuary was liable to death at the hands of Heaven, but the Sages maintained that he was merely prohibited. The Mishnah taught that a