King James Version (KJV) Authorized Version 1611

Hebrews 3:20 KJV

"But with whom was he grieved forty years? was it not with them that had sinned, whose carcases fell in the wilderness?"

Hebrews Chapter 3, Verse 20

Hebrews 3:20 in Context (Verses 17–19 KJV)

But with whom was he grieved forty years? was it not with them that had sinned, whose carcases fell in the wilderness?

And to whom sware he that they should not enter into his rest, but to them that believed not?

So we see that they could not enter in because of unbelief.