Also, Yosef had taken leave of his father without escort and much had transpired. I knew of his brothers' animosity towards him. Yet, I sent him away without protection. In another Midrash , Chazal teach us that Yosef was alluding to the three calves which Avraham saw in his vision, the harbingers of the exile. A great man does not view any occurrence as the result of chance.
Nothing just happens.
One has only to open his eyes to see the whole picture. The Chafetz Chaim comments that it was no coincidence that Yaakov had studied the laws of eglah arufah with Yosef before they had parted ways - without protection. Yaakov could sympathize with the elders of the city who were enjoined to bring the calf. He blamed himself for not properly accompanying Yosef, for sending him out alone to such a hostile environment. Yosef foresaw the beginning of the exile as his father came down to Egypt.