Dates: c. 211 · Wikipedia
Summary: Tertullian of Carthage is the earliest Latin witness to the practice of
offerings for the dead. He reports it twice as established custom: the Church makes "offerings for the dead" on the
yearly anniversary of death (De Corona), and a widow "prays for his soul, and requests refreshment for him
meanwhile … and offers… on the anniversaries of his falling asleep" (On Monogamy). This is a
liturgical habit of intercession and oblation, not yet a worked-out theory of a purgatorial fire.
As often as the anniversary comes round, we make offerings for the dead as birthday honours.
— The Chaplet, or De Corona 3, historicalchristian.faith. Tertullian lists this among customs kept "from tradition" rather than express Scripture: the yearly oblation for the departed stands beside fasting practices and the sign of the cross as something the Church does habitually. The treatment of the death-day as a "birthday" (the soul's birth into the next life) shows the practice already settled by c. 211.
Indeed, she prays for his soul, and requests refreshment for him meanwhile, and fellowship (with him) in the first resurrection; and she offers (her sacrifice) on the anniversaries of his falling asleep.
— On Monogamy 10, historicalchristian.faith. Arguing (as a Montanist) against remarriage, Tertullian assumes that the proper widow keeps a continuing bond with her dead husband by intercession: she "prays for his soul," seeks "refreshment for him meanwhile" — that is, in the interval before the resurrection — and makes the annual offering for him. The argument only works because prayer and oblation for the dead were taken for granted by his readers.
inasmuch as we understand "the prison" pointed out in the Gospel to be Hades, and as we also interpret "the uttermost farthing" to mean the very smallest offence which has to be recompensed there before the resurrection, no one will hesitate to believe that the soul undergoes in Hades some compensatory discipline, without prejudice to the full process of the resurrection, when the recompense will be administered through the flesh besides.
— A Treatise on the Soul (De Anima) 35, historicalchristian.faith. Reading the warning of Matthew 5:25–26 ("till thou hast paid the uttermost farthing"), Tertullian takes the "prison" as Hades and the "farthing" as the least unpaid offence, and concludes that the soul there "undergoes … some compensatory discipline" in the interval before the resurrection. This is the one place he moves past the bare practice toward a notion of post-mortem reckoning — though note it is a discipline located in Hades and tied to his own eschatology (in which nearly every soul awaits the resurrection there), not the later Latin fire that purges the saved on the way to glory. This proof-text is weighed on its own argument page (assessment: weak — the reading works only inside Tertullian's universal-Hades scheme and against the grain of the verse's mainstream exegesis), one of the Scriptural proof-texts alongside the cleansing fire.