John Gill Commentary Genesis 24:29

"And Rebekah had a brother, and his name was Laban: and Laban ran out unto the man, unto the fountain." — Genesis 24:29 (ASV)

And Rebekah had a brother, and his name [was] Laban
Perhaps he was her only brother, or however the elder brother, the principal in the family, her father Bethuel being old: and Laban ran out :
out of his house, and out of the city of Haran: unto the man unto the well ;
this was after Rebekah had got home, and had related to the family whom she had met with at the well, and what had passed between them, as follows: