Luke 1:27

  1. to a virgin (betrothed to a man, whose name was Joseph), of the house of David, and the virgin's name was Miriam ("Mary") ...

Luke 1:32-34

  1. He (Yeshua) will be great, and will be called the Son of the Most High; and the Lord God will give Him the throne of His father David;
  2. and He will reign over the House of Jacob forever; and His kingdom will have no end."
  3. And Miriam said to the angel, "How shall this be, since I am a virgin?"

Luke 3:23-31

  1. And when He began His ministry, Yeshua ("Jesus") Himself was about thirty years of age, being supposedly the son of Joseph...

So Yeshua was not Joseph's biological son [1:34, 3:23] but He is descended from King David [1:32]. Luke's account of His descent must have been through His mother.