כֹּ֖ל בְּנֵ֣י דָוִ֑יד מִלְּבַ֥ד בְּֽנֵי־פִֽילַגְשִׁ֖ים וְתָמָ֥ר אֲחוֹתָֽם׃ (פ)
Tous ceux-là furent fils de David, sans compter les fils des concubines et Tamar leur sœur.
Ramban
AND LOTAN’s SISTER WAS TIMNA. This is analogous to the verses: And the sister of Tubal-cain was Naamah;285Above, 4:22. And their sisters were Zeruiah and Abigail;286I Chronicles 2:16. And Tamar was their sister;287Ibid., 3:9. and Serah their sister.288Genesis, 46:17. It is the custom of Scripture to trace the genealogy of a daughter through the brothers. Now it would have been proper that Timna be enumerated above with the sons of Se’ir by saying, “And Dishon, and Ezer, and Dishan289Verse 21 here. and their sister Timna.” But since she was Lotan’s sister both paternally and maternally, and not the maternal sister of the other brothers, Scripture therefore wanted to trace her genealogy through Lotan. It may be that she was Lotan’s maternal but not paternal sister and she was not the daughter of Se’ir the Horite, [and therefore could not be listed among his children].