Tertullian also references Luke 11:12 in his book Against Marcion, lib. IV, c. 26. (Adapted by me from Peter Holmes’ 1870 translation.)
“Even if he has offended, man is more friends with the Creator than with Marcion’s [demiurge] god. Therefore he knocks at the door of Him to whom he has the right to come — the One Whose gate he could find, Whom he knew owned bread, Who will be home in bed with the children Whom He had willed to be born. Even if the knock comes late, Time belongs to the Creator.
“…So recognize Him Whom you call the Creator as Father, too. It is He Who knows what His children need. For when they asked for bread, He gave them manna from heaven… not a snake instead of a fish, or a scorpion instead of an egg.
“…Marcion’s god, on the other hand, doesn’t even have a scorpion to give away, so he couldn’t deny what he didn’t own. Only God could do it — He who holds, but does not give out, the scorpion.”