The scriptures show this themselves. In Genesis 1-2, God is the only one mentioned as resting from work on this Sabbath. It is not until Exodus that people are told and instructed about the Sabbath. You said you couldn't find any of these scriptures but they are very easy to locate.
Mar 2:27 KJV And he said unto them, The sabbath was made for man, and not man for the sabbath:
Gen 2:2 And on the seventh day God ended his work which he had made; and he rested on the seventh day from all his work which he had made. 3 And God blessed the seventh day, and sanctified it: because that in it he had rested from all his work which God created and made.
Notice that the Seventh day was blessed and sanctified at creation.
qâdash is sanctified =
to consecrate, sanctify, prepare, dedicate, be hallowed, be holy, be sanctified, be separate
(Niphal)
to show oneself sacred or majestic
to be honoured, be treated as sacred
to be holy
(Piel)
to set apart as sacred, consecrate, dedicate
to observe as holy, keep sacred
to honour as sacred, hallow
to consecrate.
(Hithpael)
to keep oneself apart or separate
to cause Himself to be hallowed (of God)
to be observed as holy
to consecrate oneself
Origin: a primitive root
Strong's Definition: A primitive root; to be (causatively make, pronounce or observe as) clean (ceremonially or morally): - appoint, bid, consecrate, dedicate, defile, hallow, (be, keep) holy (-er, place), keep, prepare, proclaim, purify, sanctify (-ied one, self), X wholly.
When God said that He sanctified that day it wasn't for Himself. GOD IS HOLY, the day was made holy and set aside for a purpose and it wasn't because God needed a day to rest from His labour.
It was made for man. The reason it was set aside and blessed is because God rested. Resting was not nessasary but God's way of creating and pointing us to a sabbath rest, to focus on our creator.
Heb 4:4 For he spake in a certain place of the seventh day on this wise, And God did rest the seventh day from all his works.
Heb 4:9 There remaineth therefore a rest to the people of God. 10 For he that is entered into His rest, he also hath ceased from his own works, as God did from His.