Genesis 38:14 KJV [14] And she put her widow’s garments off from her, and covered her with a vail, and wrapped herself, and sat in an open place, which is by the way to Timnath; for she saw that Shelah was grown, and she was not given unto him to wife. https://bible.com/bible/1/gen.38.14.KJV
How did she know that she could trap him thus…?