Book of Enoch (1 Enoch) 73:4
And thus she rises. And her first phase in the east comes forth on the thirtieth morning: and on that day she becomes visible, and constitutes for you the first phase of the moon on the thirtieth day together with the sun in the portal where the sun rises.
Background and history of Book of Enoch (1 Enoch), and issues with this book.
R. H. Charles, The Book of Enoch (London: SPCK, 1917), public domain. The verse text is the English Wikisource transcription of that translation. Charles’s editorial signs are kept. He rearranges some verses in chapters 5, 39, 90, 91, and 106, so those chapters are not a straight 1, 2, 3 sequence.