How old was the oldest man entering the Land of Israel (other than Yehoshua and Calev) according to both Torah and Tradition?

Question

We know (Bemidbar 32:11) that the decree to die in the wilderness applied to all men twenty years old or older (other than Yehoshua or Calev):

אִם־יִרְא֨וּ הָאֲנָשִׁ֜ים הָעֹלִ֣ים מִמִּצְרַ֗יִם מִבֶּ֨ן עֶשְׂרִ֤ים שָׁנָה֙ וָמַ֔עְלָה אֵ֚ת הָאֲדָמָ֔ה אֲשֶׁ֥ר נִשְׁבַּ֛עְתִּי לְאַבְרָהָ֥ם לְיִצְחָ֖ק וּֽלְיַעֲקֹ֑ב כִּ֥י לֹא־מִלְא֖וּ אַחֲרָֽי׃

But what is the cut off for turning twenty to be included/excluded from the decree?

Does it apply to those who were under twenty on the day before leaving mitzrayim and turned twenty before the 9th of Av (or 10th?) of the second year when the decree was given (approximately 16 months later)? Or only those who turned 20 before the actual Exodus?

What is the age of the theoretical oldest man that could have entered the Land of Israel (other than Yehoshua and Calev):

1. According to the pshat in the Torah that all men over >= 20 years old were to die in the wilderness?
2. According to sources in chazal that state that others were exempt from the decree?

Answer 1

1. Focusing on the question of when the twentieth birthday had to fall, Rashi to Bamidbar 14:33 writes that the decree was such that the men died when they had entered their 60th year. This means that anyone who was aged 20 at the time of the Golden Calf (over a year prior) would eventually die in the desert, but not anyone who was not then 20, even though they had turned 20 by the time of the Spies.

I think there are a couple of ways we could understand this Rashi. It could be saying that anyone aged at least twenty at the time of the Golden Calf would die in the desert as soon as they hit 59. This would mean that anyone born on or after 17th Tammuz 2428 would survive to enter the land in Nissan 2488 aged approximately 59.5.

Alternatively, we can couple this Rashi with Ta'anit 30b (as explained by Rashi there) which records that those slated to die did so every year on 9 Av, until the final year in the desert. This means that the last ones to die were those who were in their 60th year on 9 Av 2486. Therefore anyone born on or after 10 Av 2427 would be able to enter the land in Nissan 2488 at the age of approximately 60.5.

2. As you mentioned, Chazal in Bava Batra 121b note that the decree also did not apply to the entire tribe of Levi, nor to anyone aged over 60 at the time of the decree. The gemara there records traditions that Achiyah HaShiloni, Machir ben Menashe and Yair ben Menashe were extremely old (Achiyah had known Amram, and Machir and Yair were born while Yaakov was still alive) and were still able to enter the land (without giving precise ages for any of them).

Answer 2

Note that the decree was that those that were between 20 and 60 who were eligible to be in the army were condemned to die in the desert. At each tisha b'av, those that reached 60 during the previous year died. On the year of entering the land, no-one died on tisha b'av. However, theoretically those who had been above 60 (and were now above 100), could have lived to enter the land. This means that those who were eligible to enter the army at the time of the decree all died. You should also note that since Shevet Levi were not eligible to be counted from 20 to 60, they were not included in the decree of death.

Baba Basra 121b

אמר רב המנונא לא נגזרה גזרה על שבטו של לוי דכתיב (במדבר יד, כט) במדבר הזה יפלו פגריכם וכל פקודיכם לכל מספרכם מבן עשרים שנה ומעלה מי שפקודיו מבן עשרים יצא שבטו של לוי שפקודיו מבן שלשים

Rav Hamnuna says: The decree of death pronounced for the generation of the spies was not decreed upon the tribe of Levi, as it is written: “Your carcasses shall fall in this wilderness, and all those who were counted among you, according to your whole number, from twenty years old and upward” (Numbers 14:29). The verse is interpreted: The decree applies to one whose count in the census is from the age of twenty and up, excluding the tribe of Levi, whose count is from the age of thirty and up. Ahijah was a Levite, and he was not subject to the decree.

אלא אמר רב אחא בר יעקב לא נגזרה גזירה לא על פחות מבן עשרים ולא על יתר מבן ששים לא על פחות מבן עשרים דכתיב מבן עשרים שנה ומעלה ולא על יתר מבן ששים גמר ומעלה (ויקרא כז, ז) ומעלה מערכין מה להלן יתר מבן ששים כפחות מבן כ' אף כאן יתר מבן ששים כפחות מבן עשרים

Rather, Rav Aḥa bar Ya’akov said: The decree of death was not decreed either upon those less than twenty years old or upon those more than sixty years old at the time of the sin of the spies. The Gemara explains: Not upon those less than twenty years old, as it is written: “From twenty years old and upward” (Numbers 14:29). And not upon those more than sixty years old, because he learns that there is a verbal analogy between “and upward” in the verse cited, and “and upward” from the halakhot of valuations, in the phrase: “From sixty years old and upward” (Leviticus 27:7). Just as there, concerning valuations, more than sixty years old is comparable to less than twenty years old, as there is a distinct category of those between the ages of twenty and sixty, so too here, more than sixty years old is comparable to less than twenty years old insofar as those older were not subject to the sentence. Yair, son of Manasseh, who was already older, did not die in the wilderness.