The Torah in the beginning of this week’s parshah, Parshas Toldos, tells us that Yaakov and Eisav “matured.” Rashi tells us this refers to the day Avraham Avinu passed away. Rashi further states that Hashem cut Avraham’s life short by five years so that he would not see Eisav go astray. Three pesukim earlier (Bereishis 25:27), Rashi writes that Yaakov and Eisav turned 13 years old the day Avraham Avinu died. Hashem arranged it such so that Avraham would not see Eisav performing aveiros as a gadol (mature adult).
If you were to google “How old were Yaakov and Eisav when Avraham died?” you would get the following Wikipedia answer: Since Avraham was 100 years when Yitzchak was born (Genesis 46:5), and Yitzchak was 60 years old when the twins were born (Genesis 25:26), and Abraham died at the age of 175 (Genesis 25:7), Yaakov and Eisav were 15 years old at the time of Avraham’s death.
Yet, this conclusion – based on a seemingly accurate reading of the Torah – contradicts what Rashi tells us: that they were 13 years old.
The Da’as Zekainim al Hatorah quotes the Yerushalmi which poses this very question. The Riva offers an interesting explanation to solve this dilemma. When Avraham Avinu returned from the Akeidah to the two lads waiting for him the Torah glaringly omits any mention of Yitzchak’s return. This omission is also evident in Parshash Chayei Sarah; again, the Torah makes no mention of Yitzchak’s presence at his own mother’s burial. How do we explain these omissions? The Riva states that Yitzchak did not return with Avraham Avinu after the Akeidah because he ascended to Gan Eden and remained there for two years.
The Riva explains that Yitzchak did not age the two years he spent in Gan Eden. When he returned to earth, he was the same age as when he left. So Avraham Avinu was 162 years old at the time of the birth of Yaakov and Eisav but Yitzchak was only 60 years old! Therefore, Yitzchak was 73 years old when Avraham died, and Yaakov and Eisav were actually 13 years old, as Rashi writes.
It seems clear from this explanation that time spent in heaven does not constitute time in regards to aging and other time-related calculations in this world. Parenthetically, this explanation also seems to compliment the Theory of Relativity.
Other mefarshim (Mizrachi) explain that Yaakov and Eisav were indeed 15 years old when Avraham died. Yet, although Eisav began to go astray at the age of 13, his change in direction was not immediately evident. It only became evident when he was 15, and that is when Hashem, in His kindness, removed Avraham from this earth. (This answer is also given in the Yerushalmi.)
The Nachlas Yaakov explains that although Eisav’s waywardness was evident at 13, he did not commit any cardinal sin until age 15. On the day Avraham died, = Eisav turned 15 and committed the aveiros of murder and na’arah hameurasah.