Exodus 34:27 WEB

²⁵  'You shall not offer the blood of my sacrifice with leavened bread; neither shall the sacrifice of the feast of the Passover be left to the morning.

²⁶  You shall bring the first of the first fruits of your ground to the house of Yahweh your God. You shall not boil a young goat in its mother's milk.'

²⁷  Yahweh said to Moses, 'Write you these words: for in accordance with these words I have made a covenant with you and with Israel.'

²⁸  He was there with Yahweh forty days and forty nights; he neither ate bread, nor drank water. He wrote on the tablets the words of the covenant, the ten commandments.

²⁹  It happened, when Moses came down from Mount Sinai with the two tablets of the testimony in Moses' hand, when he came down from the mountain, that Moses didn't know that the skin of his face shone by reason of his speaking with him.