Thus saith the LORD, thy redeemer, and he that formed thee from the womb, I am the LORD that maketh all things; that stretcheth forth the heavens alone; that spreadeth abroad the earth by myself;
Thus saith the Lord, thy Redeemer - confirmation of His promises to the Church and Israel, by various instances of His omnipotence: among these the restoration of the Jews by Cyrus.
I am the Lord ... that spreadeth abroad the earth by myself - by my own power. So the Chaldaic. Compare similar phrases, Hosea 8:4. Hebrew, mimeniy (H4480) х ap' (G575) emautou (G1683)] (John 5:30). So the Qeri' reads х mee'itiy (H854)]. But the Kethibh reads interrogatively х miy (H4310) 'itiy (H854)], 'Who (was) with me?' namely, in spreading abroad the earth. The sense is the same; the Kethibh is bolder and more poetic.