Matthew Henry Presbyterian @wholebiblehenry

Here is, 1. Judah's foolish friendship with a Canaanite-man. He went down from his brethren, and withdrew for a time from their society and his father's family, and got to be intimately acquainted with one Hirah, an Adullamite, Gen 38:1. It is computed that he was now not much above fifteen or sixteen years of age, an easy prey to the tempter.

Commenting on Genesis 38:1-11

John Gill Reformed Baptist @doctorgill

And she conceived, and bare a son, and he called his name Er. Which signifies a "watchman": but the reason of the name given by the Targum of Jonathan is,"because he should die without children;''as if it was the same with Ariri, "childless". And she conceived, and bare a son, and he called his name Er.

Keil & Delitzsch Lutheran @keilanddelitzsch

Gen 38:2-5 There Judah married the daughter of Shuah, a Canaanite, and had three sons by her: Ger (ער), Onan, and Shelah. The name of the place is mentioned when the last is born, viz., Chezib or Achzib (Jos 15:44; Mic 1:14), in the southern portion of the lowland of Judah, that the descendants of Shelah might know the birth-place of their ancestor.

Commenting on Genesis 38:2-5