What does Genesis 38:24 mean?
Judah's daughter-in-law tricked him. She knew where and when he'd be traveling along a certain road (Genesis 38:14), and she positioned herself there, veiled as a prostitute, and seduced him (Genesis 38:18). She accepted his staff, signet, and cord as a pledge for later payment, then disappeared back home. Because of her veil, Judah never knew she was the widow of his two deceased sons whom he had promised to marry to his third son (Genesis 38:11). It was the realization that Judah's promise was a lie (Genesis 38:14) which drove Tamar to concoct her scheme.Tamar conceived that day. From her perspective, this was the best possible outcome. Twice widowed and childless, her only prospect had been marriage to Judah's son Shelah. Now, however, she is expecting children and has powerful evidence to ensure support from the father (Genesis 38:25).
So far as Judah and the others know, Tamar is betrothed to Shelah, but living in her father's home (Genesis 38:11). News that she is pregnant raises natural questions. The conclusion—which is not incorrect—is that she's committed an act of sexual immorality. This news comes to Judah, who is incensed. Tamar is still promised to be married to Judah's son Shelah, so she would be considered guilty of a serious sin no matter how she became pregnant.
Judah's response is swift and final: Burn her to death. Customs of the time, as well as God's later law for the Israelites, would call for the death penalty in cases of adultery (Leviticus 20:10). This is remarkably hypocritical on Judah's part, as he himself is guilty of sexual immorality—he does not yet know he is the man with whom Tamar committed sin!
The sentence of death by burning, as well, is extreme. Whether Judah had enough authority to make that happen, or not, he seems to think the situation reflects poorly on him as her father-in-law. Tamar's response will expose that hypocrisy in no uncertain terms (Genesis 38:25).