I am not disagreeing with you, but I would ask how a modern follower of Jesus/Yeshuah/Yahweh is expected to act on a sabbath, and what rules (if any) are required of them. Arguing over which patriarchs observed or did not observe the sabbath is really a distraction to what should be the point.
The scriptures are filled with how to keep the Sabbath. The Sabbath is God’s holy day Isaiah 58:13 Exodus 20:10-11, Gen 2:1-3 and we are to do no secular work as it is the day to honor God and to do His ways-
Isaiah 58:13 scripture shows examples of this by going to church reading God’s Word, preaching God’s Word, reasoning with each other regarding the scriptures, prayer. It’s not too strict through as Jesus taught where we can do good on the Sabbath like helping the sick or helping a lost or wounded animal in need or picking a piece of fruit in nature and eating it. The purpose of the Sabbath is to have a day you can unplug from the world and just spend it with Jesus on the day that was set aside for this purpose that is holy, blessed and sanctified because we cannot sanctify ourselves.
Eze 20:12
Was it a sin to move it to Sunday,
Yes! No one has authority to add to the Ten Commandments or take from it
Deut 4:2 God personally wrote Exodus 31:18 and God spoke Exodus 20:1 and added no more Deut 5:22 these are God's holy commandments and are inside the Most Holy of His Temple that is in heaven
Rev 11:19 they are eternal and what defines sin when broken.
Romans 7:7 and these are the works of God
Exodus 32:16 and man is not above God.
Changing the corporate day of worship from Sabbath to Sunday is one of the devil's biggest deceptions. Something we are warned would happen in scripture
Dan 7:25, the only law that is both a time (every Sabbath day
Exodus 20:10) and a law (4th commandment
Exodus 20:8-11) is the Sabbath and we were warned it would be changed not by God and the institution who changed it freely admits that if you are keeping Sunday instead of Sabbath you are keeping a commandment of the Catholic Church and that the Catholic church had no scriptural authority to change God's Sabbath commandment and they are above God's Word. Just a few quotes
It is well to remind the Presbyterians, Baptists, Methodists, and all other Christians, that the Bible does not support them anywhere in their observance of Sunday.
Sunday is an institution of the Roman Catholic Church, and those who observe the day observe a commandment of the Catholic Church.
—Priest Brady, in an address, reported in the Elizabeth, NJ ‘News’ on March 18, 1903.
Q. Have you any other proofs that they(Protestants) are not guided by the Scripture?
A. Yes; so many, that we cannot admit more than a mere specimen into this small work. They reject much that is clearly contained in Scripture, and profess more that is nowhere discoverable in that Divine Book.
Q. Give some examples of both?
A. They should, if the Scripture were their only rule, wash the feet of one another, according to the command of Christ, in the 13th chap. of St. John; —they should keep, not the Sunday, but the Saturday, according to the commandment, "Remember thou keep holy the SABBATH-day;"
for this commandment has not, in Scripture, been changed or abrogated;...
—Rev. Stephen Keenan, A Doctrinal Catechism; New York in 1857, page 101 Imprimatuer
Question: Which is the Sabbath day?
Answer: Saturday is the Sabbath day.
Question: Why do we observe Sunday instead of Saturday?
Answer: We observe Sunday instead of Saturday
because the Catholic Church transferred the solemnity from Saturday to Sunday.
—Rev. Peter Geiermann C.SS.R., The Convert’s Catechism of Catholic Doctrine, p. 50
Q. Have you any other way of proving that the Church has power to institute festivals of precept?
A. Had she not such power, she could not have done that in which all modern religionists agree with her; —she could not have substituted the observance of Sunday the first day of the week, for the observance of Saturday the seventh day,
a change for which there is no Scriptural authority.
—Rev. Stephen Keenan, A Doctrinal Catechism; New York in 1857, page 174
Deny the authority of the Church and you have no adequate or reasonable explanation or justification for the substitution of Sunday for Saturday in the Third - Protestant Fourth - Commandment of God...
The Church is above the Bible, and this transference of Sabbath observance is proof of that fact.'
—Catholic Record, September 1, 1923.
There is clear history of the Sabbath being changed just like scripture warns us and it was changed in the third century from the Pegan ritual of sun worship. Sun worship became Sunday worship and most people followed along many thought it was better than being murdered which millions of Christians were during his time until the final change from Sabbath to Sunday. God has always had a people who kept the Sabbath commandment and all the commandments but it's always been a remnant Rev 12:17 KJV. God has people in all churches living up to the light they have, but He is calling us out of our false teachings Rev 18:4 that have been handed down to us through the centuries as we must worship God in Spirit and in Truth John 4:23-24. Jesus calls keeping man's traditions over the commandments of God worshipping in vain. Matthew 15:3-9
or should it be observed on Saturday?
Yes Exodus 20:10, we should always obey God the way He asks. In almost all ancient languages Saturday translates into Sabbath.
Do you have to prepare food the day before?
I try to. I tend not to do heavy cooking on the Sabbath.
Is pulling a weed in your back yard on the Sabbath a sin
I consider this work and something that can be done in the other six days Exodus 20:9
or is taking a hike in a park after church a sin?
I do not consider that to be a sin. Being in nature with God and enjoying everything He created for us without us is not a sin. It would not be my main event though on the Sabbath- God really wants to spend time with us on the Sabbath- He set this day aside to do so to be a blessing Isaiah 58:13-14. The Sabbath is the only commandment that points us back to our Creator. Exodus 20:11 There are many gods of this world but only one God who is capable of Creation and the Sabbath is a memorial to His creative and sanctifying power.