זוהר בראשית — דף רלא ע”ב

Egypt mourned Jacob for seventy days. Seventy corresponds to the seventy years during which the nations were privileged to mourn. The secret is that the nations weep for the righteous because the righteous protect even the nations. When the righteous man dies, evil gains dominion, for there is no one to protect them. Egypt's seventy days of mourning for Jacob testifies to his greatness which protected the peoples.