1 Enoch 6:2
1 And it came to pass when the population of humans had increased during those times, beautiful and attractive daughters were born to them. 2 And the angels, the children of heaven, saw them and desired them, and said to each other: 'Come, let us choose wives from among the humans and father children.' 3 And Semjâzâ, their leader, said to them: 'I fear that you will not actually agree to do this, and I alone will have to pay the penalty of a great sin.'
Protoevangelium of James 14
Gospel of James14 Joseph was deeply afraid and withdrew from Mary, thinking about what he should do. He said to himself, “If I cover up her supposed sin, I will be going against the law of the Lord; but if I expose her to the people of Israel, I fear that what’s inside her might be from an angel, and I’ll be responsible for condemning innocent blood to death. What should I do? I’ll quietly divorce her.” As night fell, an angel of the Lord appeared to him in a dream, saying, “Don’t be afraid to take Mary as your wife, for what’s conceived in her is from the Holy Spirit. She will give birth to a Son, and you will name Him Jesus, for He will save His people from their sins.” Joseph woke from his dream, glorifying the God of Israel for the grace he had been given, and he stayed with Mary.
Notes and References
"... the addition of the “holy” Spirit to the birth narrative tradition in a form that would eventually be adapted in the gospels suggests that the role of an angel in the annunciation to Joseph and Mary, respectively, was not, in contrast to stories known from the Hebrew Bible, found adequate enough to underscore the singularity of Jesus’ significance. Indeed, the involvement of the “holy” Spirit moves the spotlight of the story away from the role of the angel himself; moreover, we have seen that in Luke 1, the role of the Spirit functions as a way of marking out Jesus as superior to John the Baptizer. However, there is more to be said: the addition of the holy Spirit would have functioned as a corrective against a probable misconception that ancient readers and hearers familiar with Jewish apocalyptic traditions may have had some basis for inferring: namely, that the angel himself might have been involved in some way with the impregnation of Mary ... This is indeed the suspicion attributed to Joseph about what happened to Mary in the much later Protoevangelium of James 14–15 ..."
Stuckenbruck, Loren T. The Myth of Rebellious Angels: Studies in Second Temple Judaism and New Testament Texts (p. 159) Mohr Siebeck, 2014