Jesus said:"However, this kind does not go out except by prayer and fasting."
(Mat 17:21, NKJV).
This verse is excluded from several Bible translations, such as ESV and NIV.
The reason is that several of the oldest Greek manuscripts exclude this verse.
The same occurs for Mark 9:29, where NKJV says ". . . prayer and fasting." and ESV and NIV says ". . . prayer." See also the explanation of Fasting.
See why Mat 17:21 isn't in the original text explained at time 9:55–14:58 in December 2024 Bible Q&A. The same applies to Mark 9:29. See also the origins
of various Bible translations explained at Background in Bible Translations.
To summarize: While fasting can be a good thing,
it's correct to omit verse Mat 17:21 and verse Mark 9:29 should be:
"And he said to them: 'This kind cannot be driven out by anything but prayer.'"
See also Critical verses in the Gospels at the end of The Four Gospels.
