Isaac

Isaac or Yitzchak (Hebrew: יִצְחָק "he will laugh" or "he laughs") was the only son of Abraham and Sarah, and the father of Jacob and Esau as described in the Hebrew Bible. His story is told in the Book of Genesis. Isaac was the longest-lived of the patriarchs, and the only biblical patriarch whose name was not changed. Isaac was the only patriarch who did not leave Canaan, although he once tried to leave and God told him not to do so. Compared to other patriarchs in the Bible, his story is less colorful, relating few incidents of his life.

Abraham's willingness to follow God's command to sacrifice Isaac was viewed by Early Christianity as an example of faith and obedience, and is often cited today:

8 By faith Abraham obeyed when he was called to go out to a place that he was to receive as an inheritance. And he went out, not knowing where he was going. 9 By faith he went to live in the land of promise, as in a foreign land, living in tents with Isaac and Jacob, heirs with him of the same promise. 10 For he was looking forward to the city that has foundations, whose designer and builder is God. 11 By faith Sarah herself received power to conceive, even when she was past the age, since she considered him faithful who had promised. 12 Therefore from one man, and him as good as dead, were born descendants as many as the stars of heaven and as many as the innumerable grains of sand by the seashore. -Heb. 11:8-12

Etymology and meaning
The English name Isaac is a translation of the Hebrew term יִצְחָק, Strong's H3327 - Yitschaq which literally means "he will laugh," or "he laughs." The term conforms to a well-known Northwest Semitic linguist type, but is not known from elsewhere. As mentioned the term literally means "may God smile", and the Ugaritic texts from thirteenth century BCE refer to the benovolent smile of the Canaanite god El. The Bible (i.e. the canonical collections of sacred writings of Judaism), however, ascribes the laugher to be Isaac's mother (Sarah) rather than the Canaanite god El. The reason for Sarah's laughing, according to the Bible, was that, when God gave the news of the birth of Isaac to his parents they were beyond the age of having children, so they privately laughed at the prediction.

More...