וַיֹּ֕אמֶר הִנֵּה־נָ֖א זָקַ֑נְתִּי לֹ֥א יָדַ֖עְתִּי י֥וֹם מוֹתִֽי׃
Ishak berkata, “Lihatlah, aku sudah tua; aku tidak tahu kapan hari kematianku.”
Rashi
לא ידעתי יום מותי I KNOW NOT THE DAY OF MY DEATH — R. Joshua the son of Korcha said: When a person approaches the age at which his parents died he may well be anxious five years before and five years after. Isaac was then one hundred and twenty three years old and he said, “Perhaps I shall only reach the age of my mother who died at the age of 127 and I am now within five years of her age: therefore, I know not the day of my death —I may only reach the age of my mother or it may be the age of my father” (Genesis Rabbah 65:12).
Chizkuni
לא ידעתי יום מותי, I do not know when I shall die;” if I were to die suddenly, you (Esau) will lose all your money and your authority as you have sold your birthright to Yaakov. Therefore I wish to anticipate such an event by giving you my wealth while I am still alive so that Yaakov cannot deprive you of what was yours from birth. Gifts made during one’s lifetime cannot be challenged.
Rashbam
הנה נא, I beg of you, due to my old age and the fact that I want to bestow on you the blessing which is within my power to bestow, the blessing of Avraham concerning inheriting this land.