Japhia
The name Japhia attaches to three distinct figures in the UPDV: a Canaanite king of Lachish who joined the southern coalition against Joshua, a border town in the territory of Zebulun, and a son born to David in Jerusalem. The shared name groups otherwise unrelated material from Joshua, 2 Samuel, and 1 Chronicles.
King of Lachish
Japhia first appears as one of the five Amorite kings recruited by Adoni-zedek of Jerusalem to attack Gibeon after Gibeon made peace with Israel. He is named alongside Hoham of Hebron, Piram of Jarmuth, and Debir of Eglon: "Therefore Adoni-zedek king of Jerusalem sent to Hoham king of Hebron, and to Piram king of Jarmuth, and to Japhia king of Lachish, and to Debir king of Eglon, saying," (Josh 10:3).
Town of Zebulun
A place named Japhia marks the eastern boundary of Zebulun's tribal allotment. The border line runs from Sarid eastward, by way of Chisloth-tabor and Daberath, and then climbs up to Japhia: "and it turned from Sarid eastward toward the sunrising to the border of Chisloth-tabor; and it went out to Daberath, and went up to Japhia;" (Josh 19:12).
Son of David
Japhia is listed among the sons born to David in Jerusalem after the move from Hebron. The 2 Samuel roster places him with Ibhar, Elishua, and Nepheg: "and Ibhar, and Elishua, and Nepheg, and Japhia," (2Sa 5:15). The parallel Chronicler lists pair him with Nogah and Nepheg: "and Nogah, and Nepheg, and Japhia," (1Ch 3:7), and again "and Nogah, and Nepheg, and Japhia," (1Ch 14:6).