However, when they relayed all that Joseph had told them, and when he saw the wagons that Joseph had sent to carry him back, the spirit of their father Jacob was revived.
We have here the good news brought to Jacob. 1. The relation of it, at first, sunk his spirits. When, without any preamble, his sons came in, crying, Joseph is yet alive, each striving which should first proclaim it, perhaps he thought they bantered him, and the affront grieved him; or the very mention of Joseph's name revived his sorrow, so that his heart fainted, Gen 45:26.
Commenting on Genesis 45:25-28
And they told him all the words of Joseph, which he had said unto them,.... Not concerning their selling of him, and his forgiveness of them, and reconciliation to them, which perhaps Jacob never heard of to his dying day, since he makes no mention of it, nor hints at it in his dying words to them; but of his great advancement in the court...
When he saw the wagons - the spirit of Jacob - revived - The wagons were additional evidences of the truth of what he had heard from his sons; and the consequence was, that he was restored to fresh vigor, he seemed as if he had gained new life, ותחי vattechi, and he lived; revixit, says the Vulgate, he lived afresh.