When is it permissible to depart (Daf') from Muzdalifah?

Primary text

It is not permissible to depart from Muzdalifah before midnight. If one departs afterward, there is no penalty upon him. This is the view of Al-Shafi'i. Permission to depart after midnight is granted based on established concessions (Rukhsah). Evidence includes the actions of the Prophet (peace be upon him) instructing the weak members of his family to depart early, as reported by Ibn 'Abbas and Asma', and sending Umm Salamah to throw the pebbles before dawn, as reported by 'A'ishah. If one departs before midnight without returning during the night, a sacrifice is due, but if one returns during the night, no sacrifice is required, similar to one who departed 'Arafah during the day.