Genesis 38:12-17

12And as the days were multiplied, Judah's wife, the daughter of Shua, died. And Judah was comforted, and he went up to his sheep-shearers, to Timnah, he and his friend Hirah the Adullamite.

13And it was told Tamar, saying, Behold thy father-in-law is going up to Timnah to shear his sheep.

14And she put the garments of her widowhood off from her, and covered herself with a veil, and wrapped herself, and sat in the entry of Enaim, which is on the way to Timnah; for she saw that Shelah was grown, and she was not given to him as wife.

15And Judah saw her, and took her for a harlot; because she had covered her face.

16And he turned aside to her by the way, and said, Come, I pray thee, let me go in to thee; for he did not know that she was his daughter-in-law. And she said, What wilt thou give me, that thou mayest come in to me?

17And he said, I will send [thee] a kid of the goats from the flock. And she said, Wilt thou give [me] a pledge, until thou send it?