The Historical New Testament (1901) by Professor of Greek and New Testament Exegesis James Moffatt, states: “So, besides Strauss, Hilgenfeld, and Havet (iv. p. 280), Keim, who regards it [
Mat 28:19]…(p. 647) as a wandering passage, containing a baptismal formula, which originated in the first half of the second century.”
“The use of the baptismal formula belongs to an age subsequent to that of the apostles, who employed the simple phrase of baptism into the name of Jesus...Had this phrase been in existence and use, it is incredible that some trace of it should not have survived; whereas the earliest reference to it, outside of this passage, is in Clem. Rom. and the Didache…” (p. 648).