25:9כ״ה:ט׳
1 א

יצחק וישמעאל. מִכָּאן שֶׁעָשָׂה יִשְׁמָעֵאל תְּשׁוּבָה וְהוֹלִיךְ אֶת יִצְחָק לְפָנָיו, וְהִיא שֵׂיבָה טוֹבָה שֶׁנֶּאֱמַר בְּאַבְרָהָם (בראשית רבה):

יצחק וישמעאל ISAAC AND ISHMAEL — From this we gather that Ishmael repented of his evil ways (cf.Bava Batra 16b) and yielded the precedence to Isaac. This is what is meant by the “good old age” mentioned in connection with Abraham (Genesis Rabbah 38:12).