Genesis 38:13

And it was told Tamar, saying, Behold thy father in law goeth up to Timnath to shear his sheep.

Genesis 38:13 stands in the account of the sin of Judah and of his family, an account placed between Joseph being sold into Egypt and Joseph being bought by Potiphar in Egypt. The chapter to which it belongs displays part of the sad fruits of Jacob's mistake in having more than one wife, including partiality, jealousy, envy, low moral standards, and crime. The account is recorded to reveal sin so that it may be shunned, and to reveal God's remedy in his love, mercy, and power.

The verse concerns Tamar acting the part of a harlot with her father-in-law. The episode of Tamar and Judah is the story of the birth and ancestry of Pharez, showing that Christ's human ancestry included people born amid human sin and weakness. Pharez, an ancestor of Christ according to the flesh, was born of a harlot, which proves that the human line from which Christ sprang was such as would tend to concentrate in him all the weaknesses of humanity, showing that the flesh he assumed had all the weaknesses and sinful tendencies to which fallen human nature is subject. Tamar is named among the women in Jesus' ancestry, showing that his family history included women with fallen or reproached pasts and offering hope to the fallen.

The verse is part of the history of Joseph's family. That history illustrates trust in God's guidance. It shows that God may lead a person by a winding route, but he brings them to the purpose he intends.