Genesis 38:7

And Er, Judah's firstborn, was wicked in the sight of the
Lord
That is, exceedingly wicked, as this phrase signifies, ( Genesis 13:13 ) , was guilty of some very heinous sin, but what is not mentioned; according to the Targum of Jonathan and Jarchi, it was the same with his brother Onan's, ( Genesis 38:9 ) , which it is suggested he committed, lest his wife should prove with child, and lose her beauty; but if it had been the same with his, it would have been expressed as well as his. An Arabic writer ^F16 says, that he cohabited with his wife not according to the course of nature, but in the "sodomitical" way: and the Lord slew him;
by his immediate hand, striking him dead at once, as Ananias and Sapphira were stricken, ( Acts 5:5 Acts 5:10 ) ; or by sending some distemper, which quickly carried him off, as a token of his displeasure at his sin.