Exodus 34:26-28

Young's Literal Translation

²⁶ the first of the first-fruits of the land thou dost bring into the house of Jehovah thy God; thou dost not boil a kid in its mother's milk.'

²⁷ And Jehovah saith unto Moses, `Write for thyself these words, for, according to the tenor of these words I have made with thee a covenant, and with Israel.'

²⁸ And he is there with Jehovah forty days and forty nights; bread he hath not eaten, and water he hath not drunk; and he writeth on the tables the matters of the covenant -- the ten matters.