פּירוש אויף בראשית 30:25

כאשר ילדה רחל את יוסף WHEN RACHEL HAD BORN JOSEPH — after the birth of him who was to become Esau’s adversary (Genesis Rabbah 73:7) — as it is said (Obadiah 1:18) “And the house of Jacob shall be a fire, and the house of Joseph a flame and the house of Esau for stubble“. Fire (Jacob) that has no flame (Joseph) has no effect at a distance. Therefore, when Joseph was born Jacob put his trust in the Holy One, blessed be He, and wished to return home (Obadiah 1:18).

שלחני, for now that Joseph had been born Yaakov’s second stint of 7 years labour for Lavan had come to an end.

ויהי כאשר ילדה, Yaakov told Lavan that now that all his wives and handmaids had born children including Rachel who had been barren, there was no further reason for him to detain Yaakov. There is an aggadic commentary quoted by Rashi according to which now that Joseph had been born Yaakov was reassured about his fear of Esau being able to harm him. He considered Joseph the antidote to such a danger. He had been told in a prophetic vision that the descendants of Esau would fall victim to the descendants of Joseph, and this is why he was prepared to go back now to his father’s house