Began to invoke a curse upon himself (Jerusalem Bible, Barclay, and New International Version have the equivalent of “call down curses on himself”): this appears to have God as the assumed source of the curse, and so Die Bibel im heutigen Deutsch renders the verse as “But Peter swore: ‘May God punish me if I am lying! I do not know the man!’ ” (compare Good News Translation). A different interpretation is pursued by Moffatt (“he broke out cursing and swearing”), as by Luther 1984, New English Bible, New American Bible, and Phillips.

Immediately (Good News Translation “Just then”) may be translated “as soon as he said this.”

As at verse 34, the cock is not a specific fowl previously mentioned, hence “a rooster” of Good News Translation.

Quoted with permission from Newman, Barclay M. and Stine, Philip C. A Handbook on the Gospel of Matthew. (UBS Handbook Series). New York: UBS, 1988. For this and other handbooks for translators see here .