Heb 11, 17-18 By faith Abraham offered up Isaac

(Heb 11, 17-18) By faith Abraham offered up Isaac
[17] By faith Abraham, when put to the test, offered up Isaac, and he who had received the promises was ready to offer his only son, [18] of whom it was said, "Through Isaac descendants shall bear your name."

(CCC 2570) When God calls him, Abraham goes forth "as the Lord had told him" (Gen 12:4); Abraham's heart is entirely submissive to the Word and so he obeys. Such attentiveness of the heart, whose decisions are made according to God's will, is essential to prayer, while the words used count only in relation to it. Abraham's prayer is expressed first by deeds: a man of silence, he constructs an altar to the Lord at each stage of his journey. Only later does Abraham's first prayer in words appear: a veiled complaint reminding God of his promises which seem unfulfilled (Cf. Gen 15:2 f). Thus one aspect of the drama of prayer appears from the beginning: the test of faith in the fidelity of God. (CCC 2572) As a final stage in the purification of his faith, Abraham, "who had received the promises" (Heb 11:17) is asked to sacrifice the son God had given him. Abraham's faith does not weaken (“God himself will provide the lamb for a burnt offering."), for he "considered that God was able to raise men even from the dead" (Gen 22:8; Heb 11:19) and so the father of believers is conformed to the likeness of the Father who will not spare his own Son but wiLl deliver him up for us all (Rom 8:32). Prayer restores man to God's likeness and enables him to share in the power of God's love that saves the multitude (Cf. Rom 8:16-21). (CCC 145) The Letter to the Hebrews, in its great eulogy of the faith of Israel's ancestors, lays special emphasis on Abraham's faith: "By faith, Abraham obeyed when he was called to go out to a place which he was to receive as an inheritance; and he went out, not knowing where he was to go" (Heb 11:8; cf. Gen 12:1-4). By faith, he lived as a stranger and pilgrim in the promised land (Cf. Gen 23:4). By faith, Sarah was given to conceive the son of the promise. And by faith Abraham offered his only son in sacrifice (Cf. Heb 11:17).