Job 38:7 (LXX): ὅτε ἐγενήθησαν ἄστρα ᾔνεσάν με φωνῇ μεγάλῃ πάντες ἄγγελοί μου
The sons of God are explicitly identified as angels/messengers in this verse.
Also see http://jewishchristianlit.com/Texts/StudTxts/11Q10!.html
"Where were you when I created the earth? Answer, if you can 3 who created , measurements? Or who used a tape measure? Or what are its bases set to or who set the cornerstone. 7 When the stars shown [sic] in the morning and all the angels of God song? Can you lock the entrace [sic] to the sea when it tries to leave the deep murky bottom. When did you where [?] clouds as cloths and fog as baby's cloths" (Targum of Job, Col. XXX).
See doctoral thesis here: https://ora.ox.ac.uk/objects/uuid%3A039b549f-3491-4f98-869a-33eba9d04f5a