Genesis 38:5

38:5 Then she had yet another son, whom she named Shelah. She gave birth to him in Kezib.

Genesis 38:11

38:11 Then Judah said to his daughter-in-law Tamar, “Live as a widow in your father’s house until Shelah my son grows up.” For he thought, “I don’t want him to die like his brothers.” So Tamar went and lived in her father’s house.

Genesis 38:14

38:14 So she removed her widow’s clothes and covered herself with a veil. She wrapped herself and sat at the entrance to Enaim which is on the way to Timnah. (She did this because she saw that she had not been given to Shelah as a wife, even though he had now grown up.)

Genesis 38:26-30

38:26 Judah recognized them and said, “She is more upright than I am, because I wouldn’t give her to Shelah my son.” He did not have sexual relations with her again.

38:27 When it was time for her to give birth, there were twins in her womb. 38:28 While she was giving birth, one child put out his hand, and the midwife took a scarlet thread and tied it on his hand, saying, “This one came out first.” 38:29 But then he drew back his hand, and his brother came out before him. She said, “How you have broken out of the womb!” So he was named Perez. 38:30 Afterward his brother came out – the one who had the scarlet thread on his hand – and he was named Zerah.