Isaac first appears in the Torah, in which he is the son of Abraham and Sarah, the father of Jacob and Esau, and the grandfather of the twelve tribes of Israel.

Isaac's name means "he will laugh", reflecting the laughter, in disbelief, of Abraham and Sarah, when told by God that they would have a child.

[2] Recent scholarship has discussed the possibility that Isaac could have originally been an ancestor from the Beersheba region who was venerated at a sanctuary.

Ugaritic texts dating from the 13th century BCE refer to the benevolent smile of the Canaanite deity El.

According to the biblical narrative, Abraham fell on his face and laughed when God (Hebrew, Elohim) imparted the news of their son's eventual birth.

[12] On the eighth day from his birth, Isaac was circumcised, as was necessary for all males of Abraham's household, in order to be in compliance with the Jewish covenant.

At God's command as the last of ten trials to test his faith, Abraham was to build a sacrificial altar and sacrifice his son Isaac upon it.

After he had bound his son to the altar and drawn his knife to kill him, at the last moment an angel of God prevented Abraham from proceeding.

[29] Isaac's willingness to follow God's command at the cost of his death has been a model for many Jews who preferred martyrdom to violation of the Jewish law.

[31] Rabbinic tradition gave the explanation that Isaac was almost sacrificed and anything dedicated as a sacrifice may not leave the Land of Israel.

Tertullian draws a parallel between Isaac's bearing the wood for the sacrificial fire with Christ's carrying his cross.

The Epistle of James chapter 2, verses 21–24,[40] states that the sacrifice of Isaac shows that justification (in the Johannine sense) requires both faith and works.

[43] Islam considers Isaac (Arabic: إسحاق, romanized: Isḥāq) a prophet, and describes him as the father of the Israelites and a righteous servant of God.

[citation needed] Isaac, along with Ishmael, is highly important for Muslims for continuing to preach the message of monotheism after his father Abraham.

[44] The Quran states that Abraham received "good tidings of Isaac, a prophet, of the righteous", and that God blessed them both (37:112).

And We made them leaders, guiding (men) by Our Command, and We sent them inspiration to do good deeds, to establish regular prayers, and to practise regular charity; and they constantly served Us (and Us only).And WE gave him the glad tidings of Isaac, a Prophet, and one of the righteous.Some scholars have described Isaac as "a legendary figure" or "as a figure representing tribal history, or "as a seminomadic leader".

Many of the narratives deal with the relationship between the ancestors and peoples who were part of Israel's political world at the time the stories began to be written down (eighth century B.C.E.).

A persistent theme is that of difference between the ancestors and the indigenous Canaanites… In fact, the theme of the differences between Judah and Israel, as personified by the ancestors, and the neighboring peoples of the time of the monarchy is pressed effectively into theological service to articulate the choosing by God of Judah and Israel to bring blessing to all peoples.

[48]According to Martin Noth, a scholar of the Hebrew Bible, the narratives of Isaac date back to an older cultural stage than that of the West-Jordanian Jacob.

[46] It has also been argued that the form of Isaac's name as found in the Hebrew Bible is most frequently attested in the early 2nd millennium BCE rather than in later periods.

[46] Albrecht Alt and Martin Noth hold that, "The figure of Isaac was enhanced when the theme of promise, previously bound to the cults of the 'God the Fathers' was incorporated into the Israelite creed during the southern-Palestinian stage of the growth of the Pentateuch tradition.

[46] Israel Finkelstein and Thomas Römer have proposed that Isaac might be the ancestor worshipped in Beersheba and the oldest tradition about him might be an ancestor myth dating back to at least 8th century BCE as shown in Amos 7:9, while proposing that the story about him conflicting with Abimelech, king of Gerar, and Philistines, which is the story that has possibility that Abraham cycle could have vampirized or vice versa, could have been originated and have background in 7th century BCE, and could be made to aim at justifying and legitimizing the claim of Judah over the Judahite territories that are transferred to the Philistine cities by Sennacherib because of several reasons: it was time when Gerar (Tel Haror) had the special importance and fortified Assyrian administration center; there was king of Ashdod, Ahimilki, whose name is similar to that of Abimelech; the Kingdom of Judah could have gotten back parts of Judahite territories while Judah was a compliant vassal of Assyria under Manasseh.