v1-2: The Lord's blessings, unearned and free. Men prefer to earn blessings; and so often such are found to be a waste of effort; taking time and money that cannot last. And men's achievements feed our pride.
In contrast, God's blessings are free and abundant. The promise here is of a feast (see 25.6-8; Matt 22.1-14), reflecting God's abundant generosity.Here is joyful satisfaction in God.
Although the invitation is universal, there is the condition of repentance (v6-7). The command to 'come' is repeated. God is constantly welcoming as we turn to Him and return to Him.
v3: The promise of life, an everlasting covenant, fulfilled in the risen Christ, Acts 13.34.
v4: David the forerunner of Christ, he leader and commander for the people.
v5: The blessings upon Gentiles because of Israel's exaltation; see 65.1, quoted Rom 10.20. The promises of God through Christ reach all nations.
v6-7: Mercy falls on the repentant; but the day of opportunity is not endless. There is abundant pardon, for we are abundant sinners; even the ungodly are justified through His grace and power. We must therefore turn to the Lord, and seek Him alone.
John Bunyan defines the evil man's thoughts; 'The unrighteousness man’s thoughts are ‘those thoughts that hinder the coming man in his progress to Jesus Christ, his unbelieving thoughts.’ (JohnBunyan, Come and Welcome to Jesus Christ)
v8-9: Human religion is different from true religion; God's ways are different from man's ways; they are higher than our ways. We therefore have much to learn, and dare not think that we have all the answers. Our expectations are different from His as well.
'It is a statement not of the surprise of God's mysterious providence but of the surprise of God's compassionate heart.' (Gentle and Lowly, Dane Ortlund)
v10-11: God's word accomplishes what He ordains, not necessarily the same as what we desire or even expect, for His ways are higher than ours.
His concern is that there be fruitfulness in our lives; even as rain and snow are given for this purpose. God's purpose is not actually defined here, for it is God's plans which are fulfilled.
v12: See 44.23; 51.3,11; joy throughout God's creation, because God's promises are fulfilled, and His character manifest. His promises are fulfilled in His people, and in this creation itself rejoices.
v13: Thorns and briars replaced by fruitful trees; contrast 7.23-24; and these earlier judgments will be reversed.