The emphasis in this brief section is on the faithfulness and power of God in keeping His promise and providing an heir miraculously through Sarah (17:16; 18:14). Note the threefold repetition of "as He had said,""as He had promised,"and "of which God had spoken"(vv. 1-2). The tension of anticipation finally subsides, but only temporarily.
God "visited"Sarah (v. 1, NIV). The Hebrew word translated "visited"(paqad) also appears when God intervened to save the Israelites from Egyptian bondage (50:24-25; Exod. 4:31) and when He ended a famine (Ruth 1:6). It also occurs when He made Hannah conceive (1 Sam. 2:21) and when He brought the Jewish exiles home from Babylonian captivity (Jer. 29:10). Thus its presence here highlights the major significance of Isaac's birth.
Abraham's obedience in naming his son "Isaac"(17:19) and circumcising him on the eighth day (17:12) was an expression of worship.
Isaac's name ("laughter") was appropriate for two reasons.
1. Isaac would be a source of joy to his parents as the fulfillment of God's promised seed.
2. Both Abraham and Sarah had laughed in amazement and unbelief respectively when told that God had chosen to bless them by giving them a son so late in life (17:17; 18:12).559
