It pointing to that full-time salvation rest in his one and only beloved Son, where we would rest from our own work to save, and in his coming and exceedingly costly work which saves.
We can have the assurance of salvation through Jesus .... the reality of it (full time as you call it) doesn't happen until He returns.
His word is clear .... He created the day and made it HOLY (separate and special from all the other days).
Hebrews 4
The Sabbath Rest
(
Genesis 2:1–3;
Exodus 16:22–30)
1Therefore,
while the promise of entering His rest still stands, let us be careful that none of you be deemed to have fallen short of it.
2For we also received the good news just as they did; but the message they heard was of no value to them, since they did not share the faith of those who comprehended it.
a3Now we who have believed enter that rest. As for the others, it is just as God has said:
“So I swore on oath in My anger,
‘They shall never enter My rest.’ ”
And yet His works have been finished since the foundation of the world.
4For somewhere He has spoken about the seventh day in this manner: “And on the seventh day God rested from all His works.”
c 5And again, as He says in the passage above: “They shall never enter My rest.”
6Since, then, it remains for some to enter His rest, and since those who formerly heard the good news did not enter because of their disobedience,
7God again designated a certain day as “Today,” when a long time later He spoke through David as was just stated: “Today, if you hear His voice, do not harden your hearts.”
8For if Joshua had given them rest, God would not have spoken later about another day.
9There remains, then, a Sabbath rest for the people of God. 10For whoever enters God’s rest also rests from his own work, just as God did from His.
11Let us, therefore, make every effort to enter
that rest, so that no one will fall by following the same pattern of disobedience.
Jesus kept the 7th day Sabbath .... follow the Lamb.