After Yossef reveals his identity to his brothers, he sends them to inform Yaakov that he is alive and ruling over Egypt. Initially, Yaakov is skeptical, but upon seeing the wagons Yossef sent, his spirit is revived. The Rashbam explains that these wagons, which only the Egyptian ruler could dispatch, serve as proof of Yossef's authority. Beyond this, the wagons symbolize a deeper message: Yossef's ability to thrive in Egypt without losing his identity. The similarity between the Hebrew words for wagons and heifers hints at Yossef's mastery over the Egyptian world, showing that he remained righteous and unassimilated. This reassures Yaakov that Yossef is alive both physically and spiritually, and that the future of their people in Egypt will be one of resilience and upliftment.