So we see that they could not enter in because of unbelief.
Berean Study Bible (BSB) - Hebrews 3:19 >So we see that it was because of their unbelief that they were unable to enter.
Textus Receptus (TR) - Hebrews 3:19 >Καὶ βλέπομεν ὅτι οὐκ ἠδυνήθησαν εἰσελθεῖν δι᾿ ἀπιστίαν.