Was this a standard way to prepare a sacrifice?
No. The verb used to describe the binding of Isaac is ʿqd, a term used only here in the Hebrew Bible. There are other terms that could be used to describe a similar action, but none of them is used to describe the preparation of the burnt offering, related most elaborately in Leviticus 1.1 There the basic procedure is:
- slaughter (šḥṭ) the animal,
- drain the blood,
- throw the blood against the sides of the altar,
- flay and cut the animal into pieces,
- arrange (ʿrk) the wood on the fire,
- arrange (ʿrk) the pieces on the wood, and
- burn all of it.
The sequence is similar in Leviticus 8-9. The account of Genesis 22 is quite different. The slaughter (šḥṭ) is represented by the same term (which is specific to slitting the throat, see Milgrom), but it is shifted to the end of a modified sequence. We are told that Abraham
- built the altar,
- arranged (ʿrk) the wood,
- bound (ʿqd) Isaac,
- lay Isaac on the altar,
- reached out his hand, and
- took the knife
- (in order to) slaughter (šḥṭ) his son.
From a narrative point of view, the act of šḥṭ is delayed to build suspense, pulling the reader forward in slow motion through the horror of the Abrahams's ordeal.2 In the words of Von Rad:
[O]ne can only answer all plaintive scruples about this narrative by saying that it concerns something more frightful than child sacrifice. It has to do with a road out into Godforsakenness, a road on which Abraham does not know that God is only testing him.
Why did Abraham bind his son Isaac?
- On a banal level: because Isaac was applied to the altar alive and needed to be tied down for slaughter.
- On a narrative level: in order to delay the decisive moment of death and escalate the suspense of the relentless march into "Godforsakenness".
- On a thematic level, the basic point of the aqedah is Abraham's unqualified obedience to God, although the reader is not privy to the details of his instructions. The particular act of ʿqd is no different: Abraham bound Isaac because God told him to.4
1. Another answer rightly pointed out that Psalm 118:27 may provide evidence that sacrifices were bound. This passage uses a different term for "bind", but it means something similar. The difficulty is that the apparent object -- ḥag -- doesn't normally mean "burnt-offering" (rather "festival" or "feast"). That the Hebrew is obscure is witnessed by the fact that good, modern translations differ.3 (Contrast ESV with NRSV and NIV.) Also, if this were a standard way of going about it, one would like to see some mention in the instructions of Leviticus or at least in the reports of sacrifices that occur throughout the Hebrew Bible. To my knowledge (based on lexical searches and a brief survey of Psalms and Leviticus commentaries, below), this method of preparation is nowhere else attested. (And why would it be necessary to bind what is already dead? unless the whole sequence is to change.) If Ps 118:27 indeed describes binding of a sacrifice to the altar, it seems to have been an unusual way to go about it.
2. Hebrew students are taught not to translate narrative sequences "...and....and...and...", but the relentless sequence of seven "and" verbs in these two verses isn't fully conveyed in the good English style achieved by the variation in conjunctions and syntax of most translations. See Young's Literal Translation or your interlinear of choice.
3. The LXX translator was also almost certainly looking at this same Hebrew when he wrote "συστήσασθε ἑορτὴν ἐν τοῖς πυκάζουσιν" ("celebrate the feast with thick branches" [Brenton; NETS gives the (no doubt appropriately) unintelligible, "arrange a feast with the thick ones"]).
4. I think this should apply whether one takes this at face value as an historical account or assumes it is a literary creation and applies whatever variety of redaction paradigm.
Leslie C. Allen, Psalms 101–150 (WBC; Grand Rapids: Zondervan, 2002), 160-168.
Jacob Milgrom, Leviticus 1–16 (AYB; New Haven: Yale University Press, 1974), 154-155.
Gerhard von Rad. Genesis: A Commentary (OTL; Westminster John Knox Press, 1973), 244. I unfortunately have only been able to see the limited Google books preview of this.
Gordon J. Wenham, Genesis 16–50 (Grand Rapids: Zondervan, 2000), 109.