זוהר שמות — דף מו ע”א

The Zohar explains the verse vayachamushim alu bnei Israel: it was through the Jubilee, the fiftieth sephirah, that Israel could leave Egypt, which is why they waited fifty days before receiving the Torah. Moses took Joseph s bones because Joseph had led the descent into exile and was a sign of the redemption, with Israel having sworn to do so. Studying Torah day and night is a condition for completeness, as there is no day without night and they are only complete together. At midnight, the Holy One enters the Garden of Eden to delight with the righteous, and that is when a person must rise to study Torah.