A.T. Robertson Commentary Hebrews 3:11

"As I sware in my wrath, They shall not enter into my rest." — Hebrews 3:11 (ASV)

As I sware (ως ωμοσα). "Correlating the oath and the disobedience" (Vincent). First aorist active indicative of ομνυω, old verb for solemn oath (6:13).

They shall not enter (ε εισελευσοντα). Future middle of εισερχομα with ε as an anacoluthon for the Hebrew im (not). Really it is a condition of the first class with the conclusion not expressed, common in the LXX as here (Robertson, Grammar, p. 1024).

Into my rest (εις την καταπαυσιν μου). Old word from καταπαυω (Hebrews 4:8), to give rest, in LXX, in N.T. only in Ac 7:49; Hebrews 3:4–11:11. Primarily the rest in Canaan and then the heavenly rest in which God dwells.