It is commonly known that before a farmer can plant, he has to prepare the soil.
Hard ground has to be broken up, and all the stones and weeds removed.
Then the farmer can plant seed and expect an abundant harvest. God was calling Israel to soften their hearts and remove the stones of sin and rebellion. Then, they would reap the fruit of God's love and provision. In the same way, God calls us to open our hard hearts and, by the Holy Spirit's light, confess our sins. As we do this, God prepares us for an outpouring of his love.