The Didache

And concerning baptism, thus baptize ye: Having first said all these things, baptize into the name of the Father, and of the Son, and of the Holy Spirit, in living water. But if thou have not living water, baptize into other water; and if thou canst not in cold, in warm. But if thou have not either, pour out water thrice upon the head into the name of Father and Son and Holy Spirit. But before the baptism let the baptizer fast, and the baptized, and whatever others can; but thou shalt order the baptized to fast one or two days before.