Genesis 35:28

The days of Isaac. Jacob was 120 at the death of his father (ch. 25:26). Ten years later, at the age of 130 years, he stood before Pharaoh (ch. 47:9). At that time Joseph had been governor of Egypt for nine years (ch. 45:11). Jacob was therefore 121 years old when Joseph was promoted at the age of 30 (ch. 41:46), and 108 when Joseph was sold at the age of 17 (ch. 37:2). Consequently, Isaac was 168 years of age when Joseph was sold into slavery. Since this tragic event occurred while Jacob was living at Hebron with his aged father (ch. 37:14), Isaac witnessed the grief of Jacob and survived that event for a period of 12 years.