"... One difference between the 'angels and the law' tradition and these other examples listed here is that the latter all have demonstrably extrabiblical parallels in overtly interpretive literature (i.e., not simply translations like the LXX, although that, too, is by no means devoid of interpretive characteristics). It is possible, however, that Jubilees can offer some assistance, since there the revelation given to Moses is mediated through 'the angel of the presence.' ... In 2:1, it is the angel who speaks to Moses the words he is to record, beginning with creation. Whether this theme in Jubilees reflects in any way a general understanding of angelic mediation of the law is, frankly, impossible to say. But, even though only one angel is mentioned, at least here there is a reference to concrete angelic activity on Mount Sinai. Regardless, what is clear to me is that Acts 7, Galatians 3, and Hebrews 2 are better understood within the context of early translations and Second Temple interpretive traditions ..."

Enns, Peter "Fuller Meaning, Single Goal" in Berding, Kenneth, and Jonathan Lunde, editors. Three Views on the New Testament Use of the Old Testament (p. 197) Zondervan, 2009