A fascinating fragment from Qumran (i.e., the Dead Sea Scrolls) that deserves mention is 4Q369 (4QPEnosh?) 1, II, 6–12. Here’s how it reads:
“and your good judgments you explained to him to […] 6 in eternal light, and you made him for you a first bo[rn] son […] 7 like him, to (be) a prince and ruler in all /your/inhabited world […] 8 the c[row]n of the heavens, and the glory of the clouds you have placed [on him …] 9 […] and the angel of your peace in his congregation and … […] 10 […] for him (?) righteous rules, as a father to [his] s[on] 11 his love, your soul cleaves to … […] 12 […] … for in them you [have placed] your glory […].”
Of course, nowhere does the text explicitly identify the figure as a Davidide and, though the Davidic king is associated with divine sonship (e.g., 2 Sam 7; Ps 89; etc.), it is true that language of being God’s “firstborn son” is also applied to Israel elsewhere (Exod 4:22).
Nonetheless, it seems to me that all of the evidence points in the direction of a Davidic association. For one thing, one is hard pressed to find a passage where Israel is described as a “prince” and God’s “firstborn”. The fact that language of divine sonship—specifically the term “first-born son” (cf. Ps 89:21, 26–27)—is linked with the term “prince” coheres best with Davidic traditions.
In fact, Craig Evans goes on to support a Davidic reading by pointing to three parallels with Psalm 89, which clearly has a Davidide in view:
“(1) David calls God his Father, which parallels line 10, ‘as a father to his son’; (2) the Psalmist says that God ‘will make him the first-born,’ which parallels line 6, ‘you made him a first-born son to you’; and (3) the psalmist says that God’s first-born will be ‘the highest of the kings of the earth,’ which finds a partial parallel in line 7, ‘like a prince and ruler in all your earthly land.’ From these parallels we may cautiously conclude that the ‘first-born’ of 4Q369 is either the historical David or a Davidic descendent.”
Similarly Chester wrote, “This fragment is most naturally to be understood, then, as representing expectation of a Davidic messiah who will be instrumental in bringing about the final kingdom of peace on earth.” Likewise, Collins writes: “This passage is extremely fragmentary, and the context is quite uncertain, but a prince and ruler who is treated as a firstborn son must surely be related to the Davidic line, whether past or future.”
I'm inclined to agree. What are your thoughts?
 Florentino García Martínez and Eibert J. C. Tigchelaar. The Dead Sea Scrolls Study Edition (2 vols. Leiden: Brill, 1997/1998), 2:731.
 Craig Evans, “Are the Son of God Texts at Qumran Messianic?,” in Qumran-Messianism (eds. J. H. Charlesworth, H. Lightenberger, and G. S. Oegema; Tübingen: Mohr-Siebeck, 1998), 151 (135–53).
 Andrew Chester, Messiah and Exaltation. (WUNT 207; Tübingen: Mohr Siebeck, 2007), 237.
 John Collins, The Scepter and the Star: The Messiahs of the Dead Sea Scrolls and Other Ancient Literature (ABRL; New York: Doubleday, 1995), 165.