'Day' in the Bible

Do not harden your hearts as [your fathers did] in the rebellion [of Israel at Meribah],On the day of testing in the wilderness,

But continually encourage one another every day, as long as it is called “Today” [and there is an opportunity], so that none of you will be hardened [into settled rebellion] by the deceitfulness of sin [its cleverness, delusive glamour, and sophistication].

For somewhere [in Scripture] He has said this about the seventh day: “And God rested on the seventh day from all His works”;

He again sets a definite day, [a new] “Today,” [providing another opportunity to enter that rest by] saying through David after so long a time, just as has been said before [in the words already quoted],“Today if you hear His voice,Do not harden your hearts.”

[This mention of a rest was not a reference to their entering into Canaan.] For if Joshua had given them rest, God would not speak about another day [of opportunity] after that.

who has no day by day need, like those high priests, to offer sacrifices, first of all for his own [personal] sins and then for those of the people, because He [met all the requirements and] did this once for all when He offered up Himself [as a willing sacrifice].

Not like the covenant that I made with their fathersOn the day when I took them by the handTo lead them out of the land of Egypt;For they did not abide in My covenant,And so I withdrew My favor and disregarded them, says the Lord.

not forsaking our meeting together [as believers for worship and instruction], as is the habit of some, but encouraging one another; and all the more [faithfully] as you see the day [of Christ’s return] approaching.