An earlier draft of this work was a doctoral dissertation accepted by the University of Cambridge early in 1975. In revising it for publication, I have attempted to take account of the most significant literature which has appeared since that time in this area of New Testament scholarship.

I am greatly indebted to Professor C. F. D. Moule of Ridley Hall, Cambridge, and formerly Lady Margaret's Professor of Divinity in the University of Cambridge who supervised my original research and who always made himself available to offer help and advice. My thanks go also to the editors of this monograph series, Professor R. McL. Wilson and Dr M. E. Thrall, for their very helpful comments. To my wife, Paula, belongs my deepest gratitude for her sacrifices in support of my work.