Rashi on Mishpatim 24:4

English: ויכתב משה AND MOSES WROTE [ALL THE WORDS OF THE LORD] — from בראשית up to (but not including) the account of the Giving of the Torah and he wrote down the commandments that were given to them in Marah (cf. Mekhilta on Exodus 19:10). וישכם בבקר AND ROSE UP EARLY IN THE MORNING — on the fifth of Sivan (cf. Rashi on Exodus 19:11) (Shabbos 88a).