But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin.
When the cloud is dried up off the mountain's brow, and the dew off the rock, the mountain is as great as before, and the rock as hard; but when convictions fade away from the heart of a natural man, they leave the mountain of his sins much greater, and his rocky heart much harder. It is less likely that that man will ever be saved. Just as iron is hardened by being melted and cooled again; just as a person recovering from fever relapses, and is worse than before.
(R. M. McCheyne.)
Parallel VersesKJV: But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin.
WEB: but exhort one another day by day, so long as it is called "today;" lest any one of you be hardened by the deceitfulness of sin.