Reference for Bava Batra 242:9
ומשאר שבטים לא עייל והתניא יאיר בן מנשה ומכיר בן מנשה נולדו בימי יעקב ולא מתו עד שנכנסו ישראל לארץ שנאמר (יהושע ז, ה) ויכו מהם אנשי העי כשלשים וששה איש ותניא שלשים וששה ממש דברי ר' יהודה
[this implies that a tribe] that was numbered from twenty years old and upward [came under the decree]; the tribe of Levi, [however], having been numbered<span class="x" onmousemove="('comment',' For the purpose of the Temple service. Cf. Num. IV, 23, 29, 35. ');"><sup>30</sup></span> from thirty years old, was excluded. Did none of the [members of the] other tribes<span class="x" onmousemove="('comment',' Who came out of Egypt. ');"><sup>31</sup></span> enter [the promised land]? Surely it was taught: Jair the son of Manasseh and Machir the son of Manasseh were 'born in the days of Jacob and did not die before Israel entered the [promised] land; for it is said, And the men of the Ai smote of them about thirty and six men,<span class="x" onmousemove="('comment',' Jos. VII, 5. ');"><sup>32</sup></span>