If today you hear his voice,
harden not your hearts.
If you hear the Lord calling you today, do not turn from what He is asking you to do. I think of the story of Jonah when I hear this scripture. Jonah clearly heard what God wanted Him to do for the people of Nineveh. God had decided to show mercy, but Jonah hardened his heart towards these people. Jonah took it on himself to offer condemnation where God would have mercy.
If you do not know the rest of this story I highly recommend reading it.
Where has God called you to serve others , but you harden your heart? What is God’s voice calling you to today?