The Apostolic Fathers attested to the practice in
the early church.
The Didache (Syria, 70-110) (Ch 7)
"Regarding baptism, baptize thus. After giving
the foregoing
instructions, "Baptize in the name of the
Father, and of the
Son, and of the Holy Spirit" (Mt 28:19) in
running water. But,
if you have no running water, baptize in any other;
and if you
cannot in cold water, then in warm. But, if the one
is lacking,
pour the other three times on the head 'in the name
of the
Father, and Son, and Holy Spirit'."