Jamieson, Fausset and Brown on Genesis 38:24

24. Bring her forth, and let her be burnt--In patriarchal times fathers seem to have possessed the power of life and death over the members of their families. The crime of adultery was anciently punished in many places by burning (Le 21:9; Jud 15:6; Jr 29:22). This chapter contains details, which probably would never have obtained a place in the inspired record, had it not been to exhibit the full links of the chain that connects the genealogy of the Saviour with Abraham; and in the disreputable character of the ancestry who figure in this passage, we have a remarkable proof that "He made himself of no reputation" [Php 2:7].