Genesis 29:29
And Laban gave to Rachel his daughter Bilhah his handmaid to be her maid.
Genesis 30:3-8
And she said, "Behold my maid Bilhah. Go in unto her, and she shall bear upon my knees, that I may also have children by her."
And she gave him Bilhah her handmaid for a wife; and Jacob went in unto her.
And Bilhah conceived and bore Jacob a son.
And Rachel said, "God hath judged me, and hath also heard my voice and hath given me a son." Therefore she called his name Dan [that is, Judging].
And Bilhah, Rachel's maid, conceived again and bore Jacob a second son.
And Rachel said, "With great wrestlings have I wrestled with my sister, and I have prevailed." And she called his name Naphtali [that is, My wrestling].
Genesis 35:22
And it came to pass, when Israel dwelt in that land, that Reuben went and lay with Bilhah, his father's concubine; and Israel heard it. Now the sons of Jacob were twelve.
Genesis 35:25
and the sons of Bilhah, Rachel's handmaid: Dan and Naphtali;
Exodus 1:2
Reuben, Simeon, Levi and Judah,