When his followers exclaim that they want to be baptized, Alma does something without precedence in any of the standard works—he baptizes himself.
“And now it came to pass that Alma took Helam, he being one of the first, and went and stood forth in the water, and cried, saying, ‘O Lord, pour out thy Spirit upon thy servant, that he may do this work with holiness of heart.’ And when he had said these words, the Spirit of the Lord was upon him, and he said, ‘Helam, I baptize thee, having authority from the Almighty God . . ..’ And after Alma had said these words, both Alma and Helam were buried in the water; and they arose and came forth out of the water rejoicing, being filled with the Spirit.” (Mosiah 18:12-14)
Although there is no other instance of this occurring in the standard works, there is one recounting of such an auto-baptism in the apocryphal Acts of Paul, involving a female disciple named Thecla, who was supposed to be in the process of being martyred by the Romans:
The Acts of Paul, Chapter 9
6 Afterwards they brought out many other wild beasts; but Thecla stood with her hands stretched towards heaven, and prayed; and when she had done praying, she turned about, and saw a pit of water, and said, Now it is a proper time for me to be baptized.
7 Accordingly she threw herself into the water, and said, In thy name, O my Lord Jesus Christ, I am this last day baptized. The women and the people seeing this, cried out, and said, Do not throw yourself into the water. And the governor himself cried out, to think that the fish (sea-calves) were like to devour so much beauty.
8 ¶ Notwithstanding all this, Thecla threw herself into the water, in the name of our Lord Jesus Christ.
9 But the fish (sea-calves,) when they saw the lighting and fire, were killed, and swam dead upon the surface of the water, and a cloud of fire surrounded
No less an authority than the Oxford Bible Dictionary regards Thecla’s “auto-baptism” as a “unique act.” Oxford Bible Dictionary, p. 1309.
A “unique act,” that is, except for one other apparent mention—in the Book of Mormon.
All the Best!
--Consiglieri