Chapter 26.
50 Also another Lucius of Membresa said: "It is written, 'God hears not sinners.' How can he who is a sinner be heard in baptism?"
51. We answer: How is the covetous man heard, or the robber, and usurer, and murderer? Are they not sinners? And yet Cyprian, while he finds fault with them in the Catholic Church, yet tolerates them.
Source: On Baptism, Against the Donatists (New Advent)