Twice in 1 Chronicles, David says he was prevented from building the temple because he shed “copious” blood (22:6–11; 28:2–7). The passages frame his final arrangements for the temple and his succession exhortations to Solomon. After analyzing the texts, Donald Murray concludes that “the core of [Yahweh's] objection to David’s building the temple is the fact that he has shed much blood.” War is mentioned, but only to explain the specific occasions for bloodshed: The references to war are “each so closely juxtaposed with those to his shedding blood as to induce the pragmatic inference that the former define and delimit the occasions of the bloodshed.”
Commentators should be more shocked at David's self-accusation than they are. Murray notes that the phrase “shed blood” (shaphak dam) is used thirty-three times in the Hebrew Bible, fifteen times with reference to violent death. The phrase typically means murder or man-slaying: In the “overwhelming majority of instances the expression designates lethal violence penetrated by ordinary citizens in civil-religious life against other ordinary members of the community not deserving of death.” Shedding blood “constitutes a heinous offence that merits both human and divine condemnation, and incurs the penalty of death for the perpetrator.” Solomon accuses Joab of “shedding blood,” emphasizing that he sheds the blood of war in peace. Executing Joab is not “shedding blood.”
That David would confess to a crime is itself surprising. Equally surprising is the fact that his guilt for blood-shed is linked to war. Only three instances of the phrase refer to violent killing in war, twice in Psalm 79 and once in Joel: “The warriors in Ps 79,3.10 are the nations, God’s enemies, and the context is one of appeal to YHWH to avenge the undeserved slaughter of his not-so-guilty servants. In Joel 4,19 [3,19] Egypt and Edom are threatened with desolation for their bloody violence against the innocent of Judah.”
That is to say, “never, outside of Chronicles, used to denote killing by Israelite warriors in the context of war.” Typically, killing in war is “conceived of as belonging to a sphere of their own where they are not criminal offences, and thus neither incur bloodguilt nor are subject to the process of blood-vengeance.” Israelite warriors smite, kill, strike, gain victories. Apart from David's usage in Chronicles, they never “shed blood.”
To explain David's usage, Murray turns to Numbers. Numbers 35:33–34 uses the expression “shed blood,” and indicates that blood pollutes the land and requires atoning cleansing. Executing the blood-shedder is the solution: Blood will have blood, blood cleanses blood. Since the land is Yahweh's, the land of His dwelling, blood pollution is a particular danger. If it is not cleansed, Yahweh threatens to abandon the land. As Murray puts it, blood shed is “a religious pollution that banishes the presence of YHWH from his land and his people.” This is one reason why David cannot built the temple: It's “absolutely imperative that such an offence should not be built as it were into the very foundations of the building that is supremely to manifest YHWH’s presence among his people.”
Why would David's wars lead to this danger? Murray points to Numbers 31:19–20, which prescribes a “decontamination” rite for warriors who have killed in war. The rite involves purification on the third and seventh days, a rite that resembles the purification from corpse defilement in Numbers 19. Murray draws the natural inference that “The law in Num 19, as the details in 19,14–18 indicate, applies to those contaminated by a corpse in civil life; the law in Num 31,19–24 to those so contaminated in a military situation.” He brings in Numbers 5:2 as well, which excludes anyone “unclean because of a dead person” from the camp. Numbers 35 defines “shed blood” as “anyone who strikes someone dead,” while Numbers 31 uses essentially the same expression to describe warriors defiled by corpses.
Murray's argument has the virtue of highlighting the oddity of David's words, and the severity of the charge. His appeals to Numbers are persuasive. But he doesn't answer some obvious questions: Why can't David's bloodshed be purified? If a warrior can be cleansed from corpse defilement, why not David? How much of the blood David shed was shed on the land? He pushed back Philistines from their incursions into Israel (1 Chronicles 14:8–17), but the main wars (recorded in 1 Chronicles 18–20) took place elsewhere. Finally, David set up an ark-shrine in Jerusalem, and seems to have had direct access to the Lord's presence (1 Chronicles 17:16), at least on one occasion. If he can do that, and lead Israel's processions and acts of worship, why can't he build a temple? Can he be too impure to build and yet pure enough for his other acts of cultic leadership?
I don't know how to answer all these questions, but let's try this on for size: David's inability to build the temple is part of a Moses-typology that runs through the Chronicler's depiction of David: As Moses was not permitted to enter the land, so David wasn't able to build the temple. The two situations are more deeply analogous than they might appear, given that Solomon's temple completes the conquest and given the analogies between Moses/Joshua and David/Solomon (Moses/David says “be strong and courageous” to Joshua/Solomon). Moses dies with the rebels and doesn't enter the rest of the land; David doesn't enter into the rest of the temple.
Now, move ahead to the end of Chronicles, and the situation of the Chronicler himself: The Davidic dynasty is interrupted. Now a second temple is being built, not only without David's help but without the help of any Davidic king (though Zerubbabel is descended from David). David's exclusion from building the first temple is matched by the exclusion of Davidic kings from the second temple.
And this exclusion is linked, if sometime loosely, to abuse of the land. In Chronicles, the abuse is a failure to give the land rest (2 Chronicles 36:20–21). Because the Davidic kings failed to give the land rest, they aren't allowed to re-enter as kings when Israel recovers the land. The analogy is closer if we incorporate Kings, which emphasizes that the Davidic dynasty falls because of the shedding of innocent blood (2 Kings 24:4).
That line of thought doesn't answer all the puzzles, and it may be mistaken. But perhaps it's a start.
(Murray, “Under YHWH's Veto: David as Shedder of Blood in Chronicles,” Filologia Neotestamentaria 82 : 457–76.)