The Last Testament of Reuben 3: 11-15; For had I not seen Bilhah bathing in a covered place, I had not fallen into this great iniquity. For my mind taking in the thought of the woman's nakedness, suffered me not to sleep until I had wrought the abominable thing. For while Jacob our father had gone to Isaac his father, when we were in Eder, near to Ephrath in Bethlehem, Bilhah became drunk and was asleep uncovered in her chamber. Having therefore gone in and beheld her nakedness, I wrought the impiety without her perceiving it, and leaving her sleeping I departed. And forthwith an angel of God revealed to my father concerning my impiety, and he came and mourned over me, and touched her no more.
The last Testament of Benjamin 1: 1; The record of the words of Benjamin, which he set forth to his sons, after he had lived a hundred and twenty years. And he kissed them, and said: As Isaac was born to Abraham in his hundredth year, so also was I to Jacob. Now since Rachel died in giving me birth, I had no milk; therefore I was suckled by Bilhah her handmaid. For Rachel remained barren for twelve years after that she had borne Joseph.
Bilhah the mother of Dan and Naphtali, who were born before Joseph, had remained barren longer than Rachel, who died near to Ephrath in Bethlehem.