וְכִי־תָבֹ֣אוּ אֶל־הָאָ֗רֶץ וּנְטַעְתֶּם֙ כָּל־עֵ֣ץ מַאֲכָ֔ל וַעֲרַלְתֶּ֥ם עָרְלָת֖וֹ אֶת־פִּרְי֑וֹ שָׁלֹ֣שׁ שָׁנִ֗ים יִהְיֶ֥ה לָכֶ֛ם עֲרֵלִ֖ים לֹ֥א יֵאָכֵֽל׃
And when ye shall come into the land, and shall have planted all manner of trees for food, then ye shall count the fruit thereof as forbidden; three years shall it be as forbidden unto you; it shall not be eaten.
Mishnah Orlah
One who plants [a fruit tree] as a fence or to provide wood beams, it is exempt from [the law of] orlah. Rabbi Yose says: even if he said “The inward [facing part of the tree] is for food, and the outward [facing part] is for a fence,” the inward [facing part] is subject [to orlah], and the outward [facing part] is exempt.
Mishnah Sheviit
Up until when are they called saplings? Rabbi Elazar ben Azariah says: until they are permitted for common use. But Rabbi Joshua says: until they are seven years old. Rabbi Akiba says: [the word] sapling, [it goes] according to its name. A tree which had been cut down and then produced fresh shoots: if one handbreadth or less, they are regarded as saplings, if more than a handbreadth they are regarded as trees, the words of Rabbi Shimon.
Pirkei Avot
He used to say: At five years of age the study of Scripture; At ten the study of Mishnah; At thirteen subject to the commandments; At fifteen the study of Talmud; At eighteen the bridal canopy; At twenty for pursuit [of livelihood]; At thirty the peak of strength; At forty wisdom; At fifty able to give counsel; At sixty old age; At seventy fullness of years; At eighty the age of “strength”; At ninety a bent body; At one hundred, as good as dead and gone completely out of the world.