Hebrews 3:15

‘In that it is said, “Today if you will hear his voice, Harden not your hearts, as in the provocation.”

The quotation is a repetition of Hebrews 3:7. ‘In that it is said’ perhaps refers back to ‘exhort one another’ (Hebrews 3:13), giving a reason for the exhortation. They are to exhort and encourage one another because the Holy Spirit has said, ‘Today if you will hear His voice, do not harden your hearts, as in the provocation.’ They are to work together to obey Him. Or it may refer back to the ‘confidence’ to which they were to hold fast.

The point is that the provocation took place in the face of God’s great and wonderful deliverance. Their past experience of God should have bolstered their faith for the present. But because hardship came, instead of encouraging each other to trust their great God in the midst of their difficulties they looked at their present hardships and hardened their hearts, and encouraged each other to murmur. In spite of the wonders they had previously seen in Egypt and at the Reed Sea, they murmured against God. They revealed an evil heart of disbelief and disobedience, not a heart of trust and faith in God, resulting in faithfulness in response. They demonstrated that instead of being caught up in love for God in view of what He had done for them, so that all else was seen in that light, they were just taken up with themselves and their own short term advantage. Let anything go wrong and His past goodness was forgotten immediately. This also was what the recipients of the letter were set on doing, and, if they went through with it, it would demonstrate where their confidence lay.

The Widespread Nature of The Punishment; The Majority Can Be Wrong (Hebrews 3:16-19).