Genesis 38:8, 11, 26

Then Judah told Onan, “Go in to your brother’s widow, and perform your duty as a brother-in-law [under the levirate marriage custom]; [be her husband and] raise children for [the name of] your brother.” [Deut 25:5-10]

Then Judah said to Tamar, his daughter-in-law, “Remain a widow at your father’s house until Shelah my [youngest] son is grown”; [but he was deceiving her] for he thought that [if Shelah should marry her] he too might die like his brothers did. So Tamar went and lived in her father’s house.

Judah recognized the articles, and said, “She has been more righteous [in this matter] than I, because I did not give her to my son Shelah [as I had promised].” And Judah did not have [intimate] relations with her again.