This word really argues against it meaning a weekly sabbath because 1) it is derived from G4521, the normal word used for a weekly sabbath, and 2) it is only used once in the entire bible (Hebrews 4:9), which indicates it has a special meaning.
Hebrews 4
1Therefore, while the promise of
entering his rest still stands, let us fear lest any of you should seem to have failed to reach it. 2For
good news came to us just as to them, but
the message they heard did not benefit them, because they were not united by faith with those who listened.a 3For
we who have believed enter that rest, as he has said,
“As I swore in my wrath,
‘They shall not enter my rest,’”
although his works were finished from the foundation of the world. 4For he has somewhere spoken of the seventh day
in this way: “And God rested on the seventh day from all his works.” 5
And again in this passage he said,
“They shall not enter my rest.”
6Since therefore
it remains for some to enter it, and those who formerly received the good news
failed to enter because of disobedience, 7
again he appoints a certain day, “Today,” saying through David so long afterward, in the words already quoted,
“
Today, if you hear his voice,
do not harden your hearts.”
8For
if Joshua had given them rest, God would not have spoken of
another day later on. 9 So then,
there remains a Sabbath rest for the people of God, 10
for whoever has entered God’s rest has also rested from his works as God did from his.
11Let us therefore
strive to enter that rest, so that no one may fall by the same sort of disobedience. 12For the word of God is living and active, sharper than any two-edged sword, piercing to the division of soul and of spirit, of joints and of marrow, and discerning the thoughts and intentions of the heart. 13And no creature is hidden from his sight, but all are naked and exposed to the eyes of him to whom we must give account.
.......
For we who have believed enter that rest, as he has said,
“As I swore in my wrath,
‘They shall not enter my rest,’”
should this have said something like:
For we who have believed keep the 7th day sabbath, as he has said,
“As I swore in my wrath,
‘They shall not keep my 7th day sabbath,’”
......
Since therefore it remains for some to enter it, and those who formerly received the good news failed to enter because of disobedience, again he appoints a certain day, “Today,” saying through David so long afterward, in the words already quoted,
should this have said something like:
Since therefore it remains for some to keep the 7th day rest (sabbath), and those who formerly received the good news failed to keep the day of rest (the 7th day) because of disobedience, again he appoints a certain day, concerning His rest, “Today,” saying through David so long afterward, in the words already quoted, Today is the 7th day sabbath you must enter.
......
For if Joshua had given them rest, God would not have spoken of another day later on. So then, there remains a Sabbath rest for the people of God, for whoever has entered God’s rest has also rested from his works as God did from his.
Let us therefore strive to enter that rest
can we in good conscience insist this means Saturday.
it is talking about Gods rest.
and is immediately followed by:
Hebrews 4
Jesus the Great High Priest
14 Since then we have a great high priest who has passed through the heavens, Jesus, the Son of God, let us hold fast our confession. 15 For we do not have a high priest who is unable to sympathize with our weaknesses, but one who in every respect has been tempted as we are, yet without sin. 16 Let us then with confidence draw near to the throne of grace, that we may receive mercy and find grace to help in time of need.
Matthew 11
27 All things are delivered to me of my Father: and no man knows the Son, but the Father; neither knows any man the Father, save the Son, and he to whomsoever the Son will reveal him. 28
Come to me, all you that labor and are heavy laden, and
I will give you rest. 29 Take
my yoke on you, and learn of me; for I am meek and lowly in heart:
and you shall find rest to your souls.
Hebrews 4
1 Therefore,
while the promise of entering his rest still stands, let us fear lest any of you should seem to have failed to reach it. 2For
good news came to us just as to them, but the message they heard did not benefit them, because they were not united by faith with those who listened....
For we who have believed enter that rest