וַיְהִ֕י מִקֵּ֖ץ אַרְבָּעִ֣ים שָׁנָ֑ה וַיֹּ֤אמֶר אַבְשָׁלוֹם֙ אֶל־הַמֶּ֔לֶךְ אֵ֣לֲכָה נָּ֗א וַאֲשַׁלֵּ֛ם אֶת־נִדְרִ֛י אֲשֶׁר־נָדַ֥רְתִּי לַֽיהוָ֖ה בְּחֶבְרֽוֹן׃
사 년만에 압살롬이 왕께 고하되 내가 여호와께 서원한 것이 있사오니 청컨대 나로 헤브론에 가서 그 서원을 이루게 하소서
Rashi on II Samuel
At the end of forty years. [After] Yisroel had asked Shmuel for a king this rebellion and weakening of the kingdom occurred.2This is the opinion of Rebe Nehuroi in the name of Rebbe Yohoshua brought in Temurah 14b. Rashi is explaining that these forty years are not describing how long Avsholom was engaged in his intriguing against the king. Rather, the verse is informing us that forty years after their improper request, the kingdom was weakened.
Rashi on II Samuel
And fulfill the vows [of bringing sacrifices] Our Rabbis said, "[Avsholom wanted] to bring lambs from Chevron3Ibid. because there, the lambs were fat."4Rashi there brings the Talmud in Menachos 87a that discusses the quality of the lambs of Chevron.