Exodus 16

Exodus 16:28 Then the Lord said to Moses, "How long will you reuse to keep my commandments and laws? Take note! The Lord has given you the sabbath. That is why on the sixth day he gives you food for two days. On the seventh day everyone is to stay home and no one is to go out."

God has given the people of Israel a test, to see if they listen to his instructions. Here it is to rest and keep the sabbath, which is one of our commandments. 

At the bottom of my pages in my bible, I have some footnotes. For this chapter, one foot or reads: "On the fifteenth day of the second month: just one full month after their departure from Egypt. They encamped in the desert of Sin on a Friday; th murmuring occurred on the sabbath, th arrival of quail th evening before Sunday, followed by six mornings of collecting manna before he next sabbath."

It is interesting the desert's name is Sin. Also, the description of the timeline has me to understand the sabbath as being Saturday at this point. Does your church consider the sabbath as being Saturday our Sunday today? 

http://www.ucg.org/booklet/sunset-sunset-gods-sabbath-rest/sabbath-beginning/which-day-sabbath/

Here is what I found on the matter. Interesting.