Pilip Comfort complete article and my comments

John 5:3–4

Wescott &Hort and Nestle Aland United Bible societies current combined best texts referred to as eclectic texts omit parts of John 5:3–4 why the water is stirred up, not John 5:7 which verifies the water gets stirred up but how it happens is it an angel of the Lord?
𝔓66 𝔓75 א A* B C* L T  Coptic these are older manuscripts ranging from 100-900’s AD whereas 100 AD is much older than 8-900 AD — there are lists of complicated rules governing these things
NKJVmg RSV NRSV ESV NASBmg NIV TNIV NEB REB NJB NAB NLT HCSBmg NET

variant 1 include only John 5:3
D W 33
none

variant 2 inincludesnly John 5:4
A* L
none

variant 3/TR include 5:3b–4, with different variations in later manuscripts—printed in TR thus:
εκδεχομενων την του υδατος κινησιν 4αγγελος γαρ κατα καιρον κατεβαινεν εν τη κολυμβηθρα, και εταρασσεν το υδωρ· ο ουν πρωτος εμβας μετα την ταραχην του υδατος, υγιης εγινετο, ω δηποτε κατειχετο νοσηματι
“waiting for the movement of the water. 4 For an angel went down at a certain season into the pool and stirred up the water; whoever then first stepped in, after the stirring up of the water, was made well from whatever disease he was afflicted with.”
A2 C3 L Θ Ψ 078vid Maj it and other versions including
KJV NKJV RSVmg NRSVmg ESVmg NASB NIVmg TNIVmg NEBmg REBmg NJBmg NABmg NLTmg HCSB NETmg

This portion (5:3b–4) was probably not written by John, because it is not found in the earliest manuscripts (𝔓66 𝔓75 א B C* T), and where it does occur in later manuscripts it is often marked with obeli (marks like asterisks) to signal spuriousness (so Π 047 syr marking 5:4). The passage was a later addition—even added to manuscripts, such as A and C, that did not originally contain the portion. This scribal gloss is characteristic of the expansions that occurred in gospel texts after the fourth century. The expansion happened in two phases: First came the addition of 5:3b—inserted to explain what the sick people were waiting for; and then came 5:4—inserted to provide an explanation about the troubling of the water mentioned in 5:7. Of course, the second expansion is fuller and more imaginative. Nearly all modern textual critics and translators will not accept the longer portion as part of the original text. NASB and HCSB, however, continue to retain verses in deference to the KJV tradition.

Comfort, Philip W. New Testament Text and Translation Commentary: Commentary on the Variant Readings of the Ancient New Testament Manuscripts and How They Relate to the Major English Translations. Carol Stream, IL: Tyndale House Publishers, Inc., 2008. Print.