Hebrews 4:3 in Greek:
εἰσερχόμεθα γὰρ εἰς τὴν κατάπαυσιν οἱ πιστεύσαντες, καθὼς εἴρηκεν, Ὡς ὤμοσα ἐν τῇ ὀργῇ μου, εἰ εἰσελεύσονται εἰς τὴν κατάπαυσίν μου. καίτοι τῶν ἔργων ἀπὸ καταβολῆς κόσμου γενηθέντων·
This is how some translate it:
For we which have believed do enter into rest, as he said, As I have sworn in my wrath, if they shall enter into my rest: although the works were finished from the foundation of the world.
The genitive absolute is "καίτοι τῶν ἔργων ἀπὸ καταβολῆς κόσμου γενηθέντων".
It starts with "καίτοι". Does it have the meaning of 'although', 'and yet', 'nevertheless', 'and indeed' or 'and further'? (see http://studybible.info/strongs/G2543) Which of them is fitting?
And what does "γενηθέντων" say? Does it say that the works were finished in the past or is it a gnomic aorist? Wikipedia says the following about the gnomic aorist: "A gnomic aorist [...] expresses the tendency for certain events to occur under given circumstances and is used to express general maxims." (http://en.wikipedia.org/wiki/Gnomic_aspect) If "γενηθέντων" says that the works are finished repeatedly under certain circumstances since the foundation of the world, it deals with the Sabbath.
And what is the clause on which the genitive absolute depends? Is it "εἰ εἰσελεύσονται εἰς τὴν κατάπαυσίν μου"? Or does it depend on more?
According to Hebrews 4:2-3 the quotation of psalm 95 "εἰ εἰσελεύσονται εἰς τὴν κατάπαυσίν μου" says that all who believe the gospel enter into the rest. Does the genitive absolute say that this quotation also refers to the works which are finished every seventh day since the foundation of the world? So is God’s rest the rest of the gospel and the Sabbath rest?
To sum up, what is the genitive absolute about and what does it say?