Abraham"s life ended with happiness, success, and a strong character. In contrast, physical and spiritual decay marked Isaac"s old age. [1][source]
"In this the infirmity of his [2] flesh is evident. At the same time, it was not merely because of his partiality for Esau, but unquestionably on account of the natural rights of the firstborn, that he wished to impart the blessing to him, just as the desire to do this before his death arose from the consciousness of his patriarchal call." [3][source]
". . . Isaac"s sensuality is more powerful than his theology." [4][source]