Matthew 17:21 — “this kind goes not out but by prayer and fasting”
Modern Bibles may omit Matthew 17:21 because Reading A ends the answer at Matthew 17:20, while Reading B includes a saying about prayer and fasting. The difference concerns whether that sentence belongs in Matthew here.
What the APB prints.
Every witness, on the record.
What a blind committee did here.
The APB's translation committee works blind: it is never told it is translating the Bible, never given a book name or a verse number, and it never sees the witnesses above. Whatever it did at this verse, it did on the language alone — and its record is public.
“Included from the Faithlife/SBLGNT apparatus at Matthew 17:20 as a traditional verse addition. Witnesses: Treg, RP.”
The blind committee recorded this as a textual supplement at Matthew 17:21. Its note says it was included from the Faithlife/SBLGNT apparatus at Matthew 17:20 as a "traditional verse addition." The record names Treg and RP as witnesses and gives the pericope an audit verdict of clean.
The case for each reading.
If it migrated from Mark
The case for Reading A begins with the shape of the answer as printed by WH: it ends at verse 20, after the saying about faith like a mustard seed and moving a mountain. The apparatus likewise places ὑμῖν with WH and NA28, then records the verse as an addition with Treg and RP. On the account supplied here, the longer wording resembles Mark's saying about prayer, and the added fasting language is itself described as later in Mark 9:29. That makes migration into Matthew a live explanation: a familiar saying could have been placed after the disciples' question, turning an answer focused on little faith into one that also names prayer and fasting.
If Matthew wrote it
The case for Reading B is that Treg prints a complete sentence after the mustard-seed answer: Τοῦτο δὲ τὸ γένος οὐκ ἐκπορεύεται εἰ μὴ ἐν προσευχῇ καὶ νηστείᾳ. Its witness row says that the verse stands, and the apparatus records the same addition with Treg and RP. In this form, the disciples' inability to cast it out receives an additional, concrete answer: this kind does not go out except by prayer and fasting. The reading therefore preserves the traditional verse as part of Matthew's sequence, rather than stopping the response at verse 20. The supplied evidence also notes the possible relationship to Mark 9:29, which remains part of the question rather than a settled conclusion.
The supplied material leaves the relationship between the longer Matthew wording and Mark 9:29 unresolved. What changes is whether Matthew's answer ends with the mustard-seed saying or also contains prayer and fasting. This variant alone does not decide doctrine; doctrines rest on many passages. The immediate interpretive question is the wording and scope of this answer in Matthew 17:14-23.
Asked plainly.
Why do some modern Bibles omit Matthew 17:21?
WH and NA28 end the answer at Matthew 17:20, while Treg and RP include the sentence about prayer and fasting. The packet presents these as Reading A and Reading B without deciding between them.
What does Matthew 17:21 say in the longer reading?
Reading B says that this kind does not go out except by prayer and fasting. In the supplied apparatus, the full Greek wording is recorded with Treg and RP.
Is the fasting wording connected with Mark?
The packet says Mark's saying about prayer, with fasting added, migrates into Matthew's later manuscripts. Treg's witness note likewise describes the Matthew verse as harmonized from Mark 9:29.
More places where the manuscripts argue.
Witness readings for critical editions are quoted from the SBLGNT apparatus (CC BY 4.0); Hebrew text from the Westminster Leningrad Codex (Open Scriptures Hebrew Bible). Readings of ancient manuscripts and versions are cited as published scholarly fact with their sources linked above. Nothing on this page declares a winner — the evidence is the point.
Weigh it yourself.
The registry doesn't tell you which reading is true. It puts every witness on one page, shows what a blind committee did with the same language, and leaves the verdict where it belongs — with the reader.