Genesis 38:12-15

But quite a while later, Judah’s wife, the daughter of Shua, died; and when the time of mourning was ended, he went up to his sheepshearers at Timnah with his friend Hirah the Adullamite. Tamar was told, “Listen, your father-in-law is going up to Timnah to shear his sheep.” So she removed her widow’s clothes and covered herself with a veil, and wrapped herself up [in disguise], and sat in the gateway of Enaim, which is on the road to Timnah; for she saw that Shelah had grown up, and she had not been given to him as a wife [as Judah had promised]. When Judah saw her, he thought she was a [temple] prostitute, for she had covered her face [as such women did].