The Sabbath Day is a Protection and a blessing...

Jeremiah the Prophet - Michelangelo, Sistine Chapel ceiling

I have been teaching the Old Testament in Sunday School this year.  This morning I ran across Jeremiah's call for Judah to keep the Sabbath Day.

21 Thus saith the LORD; Take heed to yourselves, and bear no burden on the sabbath day, nor bring it in by the gates of Jerusalem;
22 Neither carry forth a burden out of your houses on the sabbath day, neither do ye any work, but hallow ye the sabbath day, as I commanded your fathers.
23 But they obeyed not, neither inclined their ear, but made their neck stiff, that they might not hear, nor receive instruction.
24 And it shall come to pass, if ye diligently hearken unto me, saith the LORD, to bring in no burden through the gates of this city on the sabbath day, but hallow the sabbath day, to do no work therein;
25 Then shall there enter into the gates of this city kings and princes sitting upon the throne of David, riding in chariots and on horses, they, and their princes, the men of Judah, and the inhabitants of Jerusalem: and this city shall remain for ever.
26 And they shall come from the cities of Judah, and from the places about Jerusalem, and from the land of Benjamin, and from the plain, and from the mountains, and from the south, bringing burnt offerings, and sacrifices, and meat offerings, and incense, and bringing sacrifices of praise, unto the house of the LORD.
27 But if ye will not hearken unto me to hallow the sabbath day, and not to bear a burden, even entering in at the gates of Jerusalem on the sabbath day; then will I kindle a fire in the gates thereof, and it shall devour the palaces of Jerusalem, and it shall not be quenched.

(Old Testament | Jeremiah 17:21 - 27)

And one from Isaiah:

13 ¶ If thou turn away thy foot from the sabbath, from doing thy pleasure on my holy day; and call the sabbath a delight, the holy of the LORD, honourable; and shalt honour him, not doing thine own ways, nor finding thine own pleasure, nor speaking thine own words:
14 Then shalt thou delight thyself in the LORD; and I will cause thee to ride upon the high places of the earth, and feed thee with the heritage of Jacob thy father: for the mouth of the LORD hath spoken it.

(Old Testament | Isaiah 58:13 - 14)

Why does the Lord require the observance of the Sabbath - a practice almost extinct in our day and time? My take is if we embrace the Sabbath (as opposed to resisting it) it gives us a greater chance at becoming holy and putting of the natural man and learning how to put God first in our lives.  It's one more effort by God to aid us in becoming unselfish - quite the unruly task for each of us near sighted mortals.   There are promised blessing for keeping the Sabbath and apparently lost blessing for not.