Genesis 45:26 - Ellicott's Commentary On The Whole Bible

Jacob’s heart fainted. — Heb., grew cold. This was not the effect of incredulity or suspicion, but of surprise. Jacob, crushed by the loss of the child who had taken the place of his beloved Rachel in his heart, had nothing left to interest him except Benjamin. When, therefore, the news come that Joseph still lives, his mind cannot open itself to receive the joyful tidings, and their first effect is to chill him with a renewed sense of his loss. It is only when he sees the wagons, and other clear proofs of the fact, that life returns to his benumbed faculties, and he becomes capable of joy.