I Chronicles 3:9 Midrash

כֹּ֖ל בְּנֵ֣י דָוִ֑יד מִלְּבַ֥ד בְּֽנֵי־פִֽילַגְשִׁ֖ים וְתָמָ֥ר אֲחוֹתָֽם׃ (פ)

All these were the sons of David, beside the sons of the concubines; and Tamar was their sister.

Read midrashic interpretation of I Chronicles 3:9: and classical rabbinic exegesis.