8 Do not harden your hearts as in the rebellion, In the day of trial in the wilderness,
The historical context here is the hardening of the Israelites at Rephidim toward God when they lacked water and criticized Moses for it (Ex 17:1-7).
8 Do not harden your hearts
It is possible for a believer to harden our soul against God. Israel grumbled against God at Rephidim because of lack of water and this led to obstinance toward God (Ex 17:1).
“Harden” refers to hardening of the will here. It is a stubbornness toward God. The heart in both the Old and New Testaments means more than emotions; it includes the thought process and the will. It is possible to become stubborn and obstinate toward God’s Word.
Believers can reach a condition of permanently disregarding God and His Word.
It is possible for the conscience to become cauterized. It is likely that some will sear their souls toward God (1 Ti 4:2). The Greek word for “seared” is scar tissue. Scar tissue on the skin does not allow us to feel an object very well; scar tissue on the soul makes us insensitive to sin and even to God Himself. There may come a day when we no longer become open to God. In that case we will be spiritually hard.