Genesis 38:23-27

Then Judah said, “Let her keep them, otherwise we will become a laughingstock. After all, I sent this young goat, but you did not find her.”

Now it was about three months later that Judah was informed, “Your daughter-in-law Tamar has prostituted herself, and behold, she is also pregnant by prostitution.” Then Judah said, “Bring her out and have her burned!”

It was while she was being brought out that she sent word to her father-in-law, saying, “I am pregnant by the man to whom these things belong.” She also said, “Please examine and see, whose signet ring and cords and staff are these?”

And Judah recognized them, and said, “She is more righteous than I, since I did not give her to my son Shelah.” And he did not have relations with her again.

It came about at the time she was giving birth, that behold, there were twins in her womb.