Tertullian, On Baptism 16
We also have a second washing, one and the same thing: the washing of blood. The Lord speaks of it: 'I have a baptism to be baptized with,' He says, even though He had already been baptized (Luke 12:50). He came through water and blood, just as John wrote, so that He might be baptized with water, glorified with blood, and thus make us called by water, chosen by blood (John 19:34-35; 1 John 5:6). He poured out these two baptisms from the wound in His pierced side, so that those who believe in His blood would be washed with water, and those who have been washed with water would also drink His blood. This is the Baptism that represents a washing not accepted and renders it lost.
Latin
Est quidem nobis etiam secundum lavacrum, unum et ipsum, sanguinis scilicet: de quo Dominus: Habeo, inquit, Baptismo tingui, cum jam tinctus fuisset. Venerat enim per aquam et sanguinem, sicut Joannes scripsit, ut aqua tingueretur, sanguine glorificaretur, proinde nos faceret aqua vocatos, sanguine electos. Hos duos baptismos de vulnere perfossi lateris emisit, quia qui in sanguinem ejus crederent, aqua lavarentur: qui aqua lavissent, etiam sanguinem potarent. Hic est Baptismus, qui lavacrum et non acceptum repraesentat, et perditum reddit.