Where is the harlot that was openly by the wayside? - Our translators often render different Hebrew words by the same term in English, and thus many important shades of meaning, which involve traits of character, are lost. In Genesis 38:15, Tamar is called a harlot, זונה zonah, which, as we have already seen, signifies a person who prostitutes herself for money. In this verse she is called a harlot in our version; but the original is not זונה but קדשה kedeshah, a holy or consecrated person, from קדש kadash, to make holy, or to consecrate to religious purposes. And the word here must necessarily signify a person consecrated by prostitution to the worship of some impure goddess.

The public prostitutes in the temple of Venus are called ἱεροδουλοι γυναικες, holy or consecrated female servants, by Strabo; and it appears from the words zonah and kedeshah above, that impure rites and public prostitution prevailed in the worship of the Canaanites in the time of Judah. And among these people we have much reason to believe that Astarte and Asteroth occupied the same place in their theology as Venus did among the Greeks and Romans, and were worshipped with the same impure rites.

Genesis 38:21 He asked the men of her place, saying, "Where is the temple prostitute who was by the road at Enaim?" But they said, "There has been no temple prostitute here."

Genesis 38:23 Then Judah said, "Let her keep them, otherwise we will become a laughingstock. After all, I sent this young goat, but you did not find her."

Genesis
The Old Testament opens very impressively. In measured and dignified language it introduces the story of Israel's origin and settlement upon the land of Canaan (Gen.--Josh.) by the story of creation, i.-ii. 4a, and thus suggests, at the very beginning, the far-reaching purpose and the world-wide significance of the people and religion of Israel. The narrative has not travelled far till it becomes apparent that its dominant interests are to be religious and moral; for, after a pictorial sketch of …
John Edgar McFadyen—Introduction to the Old Testament