was begotten not by Joseph, but by the power of the Holy Spirit while Mary was still a virgin, in fulfillment of prophecy. Thus, in mainstream Christianity, Jesus is regarded as being literally the "only begotten son" of God, while Joseph is regarded as his adoptive father. Matthew immediately follows the genealogy of Jesus with: "This is how the birth of Jesus Christ came about: His mother Mary was pledged to be married to Joseph, but before they came together, she was found to be with child through the Holy Spirit". Likewise, Luke tells of the Annunciation: "How will this be," Mary asked the angel, "since I am a virgin?" The angel answered, "The Holy Spirit will come upon you, and the power of the Most High will overshadow you. So the holy one to be born will be called the Son of God." The question then arises, why do both gospels seem to trace the genealogy of Jesus through Joseph, when they deny that he is his biological father? Augustine considers it a sufficient answer that Joseph was the father of Jesus by adoption, his legal father, through whom he could rightfully claim descent from David. Tertullian, on the other hand, argues that Jesus must have descended from David by blood through his mother Mary. He sees Biblical support in Paul's statement that Jesus was "born of a descendant of David according to the flesh". Affirmations of Mary's Davidic ancestry are found early and often. The Ebionites, a sect who denied the virgin birth, used a gospel which, according to Epiphanius, was a recension of Matthew that omitted the genealogy and infancy narrative. These differences reflect the Ebionites' awareness of Jewish law (halakhah) relating to lineage inheritance, adoption, and the status of ancestry claims through the mother. Islam The Qurʼan upholds the virgin birth of Jesus (ʻĪsā) and thus considers his genealogy only through Mary (Maryam), without mentioning Joseph. Mary is very highly regarded in the Qurʼan, the nineteenth sura being named for her. She is called a daughter of ʻImrān, whose family is the subject of the third sura. The same Mary (Maryam) is also called a sister of Aaron (Hārūn) in one place, and although this is often seen as an anachronistic conflation with the Old Testament Miriam (having the same name), who was sister to Aaron (Hārūn) and daughter to Amram (ʻImrān), the phrase is probably