1956 BC
The birth of Isaac (Hebrew: Yitzhak, meaning 'he laughs') was the fulfillment of God's promise to Abraham and Sarah. When Abraham was 100 years old and Sarah was 90, the Lord visited them as He had promised, and Sarah conceived. 'At the appointed time, about that time, the Lord dealt with Sarah as he had said to her. And Sarah bore Abraham a son in the old age, at the time of which God had said to him' (Genesis 21:1-2). Sarah laughed when she heard she would conceiveβfirst in disbelief, then in joyβand named her son Isaac accordingly. Abraham circumcised Isaac on the eighth day, as God had commanded, fulfilling the sign of the covenant.
The birth of Isaac is one of the most significant events in salvation history. It demonstrates God's power to bring life from death, to fulfill His promises against all human possibility. The Catholic Church sees in Isaac's birth a type of the Incarnation: just as Isaac was born to an elderly and barren woman through God's power, so Christ was born of the Virgin Mary through the power of the Holy Spirit. Both births defy natural expectation and demonstrate that 'with God nothing shall be impossible' (Luke 1:37).
Isaac is also the child of promise, the son through whom the covenant line continues. The contrast between Ishmael (born of the slave woman, according to the flesh) and Isaac (born of the free woman, according to the promise) is central to Paul's theology of grace versus law. Isaac represents the children of the promiseβthose who are children of God not by natural descent but by the working of His Spirit. Key Scripture: Genesis 17:19; 18:10-15; 21:1-7; Romans 9:7-9; Galatians 4:28; Hebrews 11:11-12; CCC 60