Exodus 12:18

12:18 In the first month, ¹  from the fourteenth day of the month, in the evening, you will eat bread made without yeast until the twenty-first day of the month in the evening.

Exodus 16:5

16:5 On the sixth day ²  they will prepare what they bring in, and it will be twice as much as they gather every other day.” ³ 

[12:18]  ¹ tn “month” has been supplied.

[16:5]  ² tn Heb “and it will be on the sixth day.”

[16:5]  ³ sn There is a question here concerning the legislation – the people were not told why to gather twice as much on the sixth day. In other words, this instruction seems to presume that they knew about the Sabbath law. That law will be included in this chapter in a number of ways, suggesting to some scholars that this chapter is out of chronological order, placed here for a purpose. Some argue that the manna episode comes after the revelation at Sinai. But it is not necessary to take such a view. God had established the Sabbath in the creation, and if Moses has been expounding the Genesis traditions in his teachings then they would have known about that.