The Sabbath (v. 3) was, of course, a weekly observance in contrast to the other feasts that occurred only once a year. Moses introduced the annual holidays in verse 4. God had prescribed Sabbath observance earlier (Exod. 20:8-11; 31:13-17; 35:2-3; Lev. 19:3). Evidently Moses included it in this list because like the feasts it was a day set apart to God for holy purposes. The Sabbath was a "convocation"in that the people assembled in spirit to remember God's work for them that resulted in their being able to rest. For this convocation the Israelites did not assemble around the tabernacle but observed the day in their own dwellings.
The Sabbath was the heart of the whole system of annual feasts in Israel. The other feasts all related to the central idea of rest that the Sabbath epitomized. They focused the Israelites' attention on other Sabbath-like blessings that Yahweh provided for them.256