A student who gave a presentation on the Mandaeans in my “Heresy” class used the phrase “baptism for the dead” to describe the masiqta – more frequently translated as “mass for the dead” or something similar in English.
The masiqta proper, of course, is a ritual meal which takes after someone has died, and not an immersion. But it is closely connected with the practice of offering a final baptism for those who are near death, and the belief that their baptism accompanies them on their journey into the lightworld and helps them on their way.
I’m not sure whether I had ever heard the phrase “baptism for the dead” applied to or connected with the masiqta ritual, but if I had, they had never struck me the way they did on this occasion. The phrase “baptism for the dead” is of course used by Paul in 1 Corinthians, and a lot of scholarly debate has taken place as to his meaning.
It would be interesting to explore the possibility that the Mandaean practice could have some connection with what Paul mentioned. Acts 18-19, after all, depicts Apollos as connected with a religion that knew John’s baptism but not that of Jesus. And 1 Corinthians mentions the influence of Apollos in the church there.
I’m not aware of anyone who has explored this possibility before. If anyone reading this knows otherwise, please let me know!
Of related interest, Jona Lendering drew attention to the attempt to get a mountain on Pluto to be given a Mandaean name: Krun.