Matthew Poole and continuators on Hebrews 3:19

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

The execution of the matter sworn was felt by these Hebrews, which should make them and all that read it, to dread both their Sin and Punishment, which the Gospel would as justly inflict on them, if Unbelievers. It is to be seen in God's written Record of it, and the experienced downfall of such, that God's Oath had shut the Door as to their entrance there, and his Judgments consumed them in the Wilderness; because of their denial of resting on God's Word, and the impious practices that issued from it, in their rejecting Promises, rebelling against Precepts, and murmuring against Providence. God is no respecter of Persons; if we sin so against his Son and Gospel, how much sorer Punishment will overtake us? chap. 10.27, 29.