D.C. 59 is directed to the Saints who came to Zion.
1Behold, blessed, saith the Lord, are they who have come up unto this land with an a single to my glory, according to my commandments.
The Lord reviews many of the commandments with them but then spends a lot of time on the Sabbath Day. Considering that they needed to build a society and community (and grow food), it makes sense that they would need to spend a lot of time working. In fact, I bet that they wanted to work every day to ensure they would have what they needed. So, God spends a fair amount of time telling them to "rest from their labors" on the Sabbath Day and spend time doing the things of God. I think he was trying to get them to invest in not just their own spiritual matters that day but also help the spirituality of others and build the church. It takes an investment of time into going to church meetings, visiting members, etc. to build the church, and the Lord wanted that done on Sunday at the least.
Then he promises it will be worth it.
16Verily I say, that inasmuch as ye do this, the a of the earth is yours, the beasts of the field and the fowls of the air, and that which climbeth upon the trees and walketh upon the earth;
17Yea, and the herb, and the a things which come of the earth, whether for food or for b, or for houses, or for barns, or for orchards, or for gardens, or for vineyards;
18Yea, all things which come of the earth, in the season thereof, are made for the a and the b of man, both to please the eye and to c the heart;
19Yea, for a and for raiment, for taste and for smell, tob the body and to enliven the soul.
20And it pleaseth God that he hath given all these things unto man; for unto this end were they made to be used, with judgment, not to a, neither by extortion.
These are remarkable promises for not working one day during the week. Now, consider this verse:
21And in nothing doth man a God, or against none is hisb c, save those who d not his hand in all things, and e not his commandments.
22Behold, this is according to the law and the prophets
What does keeping the Sabbath Day have to do with confessing God's hand in all things? Well, if not working on Sunday leads to more success in temporal matters, doesn't it show that he is somewhat involved in those matters as well. I think that's the only conclusion you could come to. It is hard to show you believe God is involved in all things if you don't keep the Sabbath Day holy when he's asked you to.
Very timely scripture for the Saints in 1831, and it's very timely for me now as I am early in my career.