We have here the contrast between Isaac, the child of promise, and Ishmael, the fruit of unbelief. Ishmael was born as a result of impatience, the failure to wait upon the Lord. In the birth of Isaac, the initiative belonged with God, and the glory belonged to Him. In Christ, we are the children of promise – ‘children born not of natural descent, nor of human decision or a husband’s will, but born of God’ (John 1:13). God did not forget Ishmael. There were blessings for him (17-21). The difference between Ishmael and Isaac is the difference between common grace and saving grace. Many people know much of the grace of God in ‘the common things of life’ (Church Hymnary, 457). There are so many blessings for them to count. Still they fail to appreciate God’s greatest gift – His Son, our Saviour, Jesus Christ. Thank God for this and that and…Jesus!