Abraham lived upto 175 years, Isaac lived upto 180 years and Israel lived upto 147 years (130+17) (Gen. 25: 7-9,& 35: 28,29 & 47: 8,9 & 28). And Moses lived upto 120 years. Except Isaac all the others mentioned above had good eye sight, and especially Moses (Duet. 34:7). We read that Moses’ eye was not dim, nor his natural force abated. Then why Isaac was suffering with blindness?
The reason is very simple and true. God loved Israel (Jacob) and hated Esau (Malachi 1: 2,3) But God is not partial, as the love and hate comes as per their nature or character. Before the birth of Esau and Jacob, when Rebekah enquired with the LORD, she was told that two nations are in her womb and the elder shall serve the younger (Gen.25: 23). So it was the will and plan of God to bless Jacob (Nation of Israel) more than Esau (Nation of Edom), as God chose Abraham and his heirs, to be His own people who will serve Him till the end, in that after Isaac, his heir was Jacob to whose generation God promised Canaan the land flowing with milk and honey to Abraham first (Gen. 15: 18-21, 26: 1-5, 35: 9-13) (Exo.6:2-8).
Esau became a cunning hunter and Jacob became a plain man dwelling in tents. Isaac loved Esau as he hunts and cooks them and gave to his father and Rebekah loved Jacob as he rears the cattle and lives with his mother. So the blessings of the father Isaac will go to Esau as Isaac loved his elder son Esau more. But God loved Jacob more, and it is the will of God to bless Jacob by the hands of Isaac, but surely against the desire of Isaac, as the heir of Abraham and Isaac. So God made Isaac blind even at 100 years and he blessed Jacob thinking it was Esau, as Rebekah acted as a tool to bring the blessings of Esau to Jacob.(Gen. 27: 1-29)
But in the case of Moses, though Moses was a man of meakness, testified by God Himself, in the waters of Meribah, instead of speaking to the rock the second time, Moses beat the rock as the first time and displeased God. Action of Moses beating the rock in the first time is equal to crucifixion of Jesus, where rock signifies Jesus, and speaking the second time is equal to claiming the blessings of the crucifixion of Jesus but beating it the second time equals to crucifixion of Jesus on the second time which reveals backsling in spiritual life (Heb. 6: 4-6). So God was not pleased on action of Moses in the second time and a chastisement came upon Moses that he cannot enter Canaan but can see it from top of a mountain! Now it became necessary to Moses to climb the mountain to see the blessed land, for which his natural force was not abated. And for seeing the whole blessed land in all directions of North, west. South and East, his eyes can not be dim but very powerful. For this reason the eyes of Moses were not dim and his natural force was not abated!
Regarding the ages of Isaac and Jacob there are some confusion and let us clarify them. Isaac got married at rthe age of forty (Gen. 25:20). Rebekah was barren for 20 years and Isaac prayed, and at the age of 60, God gave him two sons. (Gen. 25; 21, 26) When Jacob was 40 years old, he was asked to go to Laban’s house to marry his daughter and also escape from his brother Esau, when Esau married at the age of 40 (Gen. 26:34,& 27: 41-46, & 28:1,2). Jacob was in his father in law,s house for 20 years, and he served for the cattle for 6 years (7+7+6=20) after the birth of Joseph (Gen. 30: 24-28 & 31: 41). When Jacob travelled back to his father, he stayed in Succoth building a house and booths for his cattle and stayed about 10 years so that his children became adults and then he went to Shechem and bought a land and stayed there. Then after the problem of Dinah and slaghter of Shechem city by his two sons Simeon and Levi, Jacob travelled to Bethel, and went to beyond tower Edar and dwelt there for some time and finally reached Hebron where his father Isaac was living (Gen. 34:1, 25-31, & 35:1, 21, 22, 27-29).
So the calculation is Jacob married around 47 years, stayed with Laban for 13 years (20-7=13), stayed in Succoth about 10 years, stayed in Shechem and beyond tower Edar about 1 year, would be 71 years. As he was born when Isaac was 60 years, So, Isaac’s age was about 131 years. Jacob and Esau burried their father soon after Jacob’s return. Isaac was blind at 100 and expecting his home call wanted to bless Esau at 100 years. But God made him to wait till Jacob returned, and he died at the age of about 131 years, and not at 180 years.
Jacob returned to his father Isaac at the age of 71 years. Joseph’s age was 17 years (6+10+1= 17). Then Joseph was missing and reached Egypt and exalted to throne in Egypt at the age of 30, and flourished years were 7, and after 2 years of famine, Jacob went to Egypt with his whole family, and lived there 17 years and died. (40+14+30+7+2+17= 110 years.) or (71+13+7+2+17=110 years) (30-17=13)
When Joseph was born, Jacob was about 54 years(40+7+7). Joseph became ruler in Egypt at the age of 30. After 2 years of famine, preceeded by 7 years of plentiness, Jacob went to Egypt with his whole family members and lived there 17 years. (54+30+7+2+17= 110) So, Jacob’s age was about 110 years and not 147 years.
Abraham begat Isaac at 100 years, Esau and Jacob were born at 60 years of Isaac and Esau and Jacob might be 15 when Abraham died and Isaac and Ismail burried him, and hence Abraham’s age is about 175 (Gen. 25:7-9), (Acts. 11: 8,9).