The apostle begins this section of Scripture with a direct quote from Psalm 95 regarding the hardening of hearts. Which is, not listening to God through His Spirit who spoke to the ancient Israelites while they wandered in the wilderness for forty years and after when the new generation entered Canaan. There in the wilderness the Jews suffered a time that was remembered as a tragic defeat. Because they provoked God through unbelief He caused nearly all of them to perish in the wilderness (desert). The seriousness of provoking God and especially through unbelief cannot be over emphasized.