Here is where the rule comes from:be specific and link to any actual biblical versus that prohibits a priest from marrying
Luke 18:28-30 (RSV) And Peter said, “Lo, we have left our homes and followed you.” [29] And he said to them, “Truly, I say to you, there is no man who has left house or wife or brothers or parents or children, for the sake of the kingdom of God, [30] who will not receive manifold more in this time, and in the age to come eternal life.”
Matthew 19:27 Then Peter said in reply, “Lo, we have left everything and followed you. What then shall we have?” (cf. Mk 10:28)
Mark 1:29-31 And immediately he left the synagogue, and entered the house of Simon and Andrew, with James and John. [30] Now Simon's mother-in-law lay sick with a fever, and immediately they told him of her. [31] And he came and took her by the hand and lifted her up, and the fever left her; and she served them.