What is the earliest record of the Apostle John being placed in boiling oil and miraculously living? I can't find any scriptural mention of the story. The only reference I have is Tertullian:
"Since, moreover, you are close upon Italy, you have Rome, from which there comes even into our own hands the very authority (of apostles themselves). How happy is its church, on which apostles poured forth all their doctrine along with their blood; where Peter endures a passion like his Lord's; where Paul wins his crown in a death like John [the Baptist]'s; where the Apostle John was first plunged, unhurt, into boiling oil, and thence remitted to his island-exile."