Genesis 38:14
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. 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.
The verse stands in the account of the sin of Judah and his family, coming after Joseph was sold into Egypt and before Joseph was bought by Potiphar. Tamar put off her widow's garments and covered herself with a veil and wrapped herself and sat in disguise by the way to Timnath because she saw that Shelah was grown and she was not given to him to wife, and that disguise kept Judah from recognizing her. Her changed appearance did not make her unknown to God. The record of Judah's sin is included to expose wrongdoing so that it may be shunned, not to encourage or excuse it.
The verse belongs to the account of Tamar, through whom Pharez was born, and Pharez is an ancestor of Christ according to the flesh, with Tamar named by Matthew among Jesus' ancestors. Tamar acted as a harlot with her father-in-law, so that Pharez was born of a harlot. This birth belongs to the ancestry and posterity of David culminating in Christ that concentrates in him all the weaknesses, sinful tendencies, and physical and moral deterioration of fallen humanity. It proves that the flesh Christ took was not the flesh of a sinless being but the flesh of sinful man, made more subject to infirmity because the race had greatly deteriorated, so that death could have power over him and he could suffer death for sin. This degraded lineage was not accidental but necessary so he could be made like his brethren and able to sympathize with and help those tempted through weakness of the flesh.
God's inclusion of shameful lives in Christ's family history offers hope to the fallen, even to those with deeply inherited tendencies toward sin. As part of the history of Joseph, the verse shows that whatever God has intended a person for, God can be safely trusted to bring them to it. For he may lead by a roundabout way but he will guide rightly.