Because Elohim rested after Creation of all humankind and not just the creation of the Jews.        Is Yshua a Jew? Yes!       Is He the Savior of all of mankind? Yes!      Is He the Lord of the Sabbath? Yes!        Why was Sabbath created? It is for three reasons:

1) To proclaim one day a week Elohim's sovereignty

2) To unify Jew and gentile into a holy assembly to do #1

3) To put a curb on Slavery

Here is my more detailed explanation: What is the Sabbath day? A forced shutdown for workaholics and pleasure seekers or an amorous gift from the Creator for ALL HIS creatures to remember Him and to have an agreed Set-Apart day that unifies ALL of mankind? The Creator rested after the six days of ALL Creation (not just for the creation of the Jews) but He does NOT need rest! Furthermore, Y'shua taught that the Sabbath was created for man's sake not the other way around. If that is not clear enough, He taught that His Father still works on the Sabbath so does He. John 5:17. Yshua said that He is the Lord of the Sabbath and He resurrected on the Sabbath day! The Sabbath day was created as a Universal day of rest against SLAVERY! In the ancient world being a slave meant absolute subservience and unending work for one's master; the Sabbath extricated the slave once a week from subservience to his master. Thus the Sabbath essentially curbed and restricted the institution of slavery, from which we can understand its association with the exodus from Egypt. According to Exo 20:8-11, the purpose of the Sabbath is to give rest to those who must do work all other days of the week: oxen and asses, slaves and strangers. The Shabbath day was created for humankind and that it was to prevent exploitation of men and labour. Here is the proof: Exo 20:8-11 As you can see, it applied to free, slave, women, child and beast.....Are you for slavery or against it? The false teaching is that roman emperor Constantine had the authority to change the Sabbath day observance from the seventh day to the idolatrous SUN-day worship day of rest. I and my house will follow the commandments of YHWH, like Joshua the Ephraimite. Whomever wants to continue to follow the roman emperor Constantine and the Laodicean church council Canon#29 that forbade by penalty of death to meet on the seventh day in 363 AD go ahead and do as you will!