Jesus and the woman taken in adultery
Biblical scholarship has long been aware that the gospel account of the scribes and Pharisees bringing the woman taken in adultery to Jesus was not included in the earliest manuscripts of the gospel of John. In modern Bible publications the account is now commonly shown in brackets. For example, the English Standard Version (ESV), says in a footnote:
Some manuscripts do not include [John] 7:53–8:11; others add the passage here or after 7:36 or after 21:25 or after Luke 21:38, with variations in the text.
Having the account not only be missing in some manuscripts, but appearing in different places and with variations, makes it an interesting case.
The David Bentley Hart translation of the New Testament gives more detail and background to this:
There is little doubt among scholars that the episode of the woman taken in adultery was not written by the same hand that produced the surrounding text. It is not found in the earliest manuscripts of John, or in any Greek or Latin text still extant from before the fourth century. It is written in a more polished style than the rest of the text, far closer to that of Luke’s Gospel than that of John’s; and, in fact, in certain Greek and Armenian families of manuscripts the story appears in Luke—where it seems to fit better for a great many reasons—rather than in John.
It is also a passage that, in both its Lucan and Johannine exemplars, shifts between different locations in the texts; as placed here in John, it clearly interrupts Jesus’s discourse. This does not mean, however, that the episode is some late invention inserted into the text to make Jesus appear more compassionate (not necessarily his most conspicuous characteristic in the fourth Gospel). For one thing, in late antiquity—Jewish, Christian, or pagan—it would have been far more scandalous than commendable in most eyes for Jesus to have allowed an adulteress to go away not only unpunished, but entirely without rebuke.
For another, there is good reason to think the episode may in fact be drawn from an older narrative source than the Gospel itself: there is a tale of a very sinful woman that the early second-century Christian Papias mentioned as being part of the lost Gospel of the Hebrews; the Syrian Didascalia (from the third century) cites “the story of the adulteress”; the Constitutions of the Apostles (in a portion probably also from the third century) relates a similar story of a sinful woman whom Jesus refused to condemn; and both Didymus the Blind and Jerome mention the tale as appearing in many manuscripts before the end of the fourth century.
Moreover, the earliest texts of John do not merely lack the story; in its place are diacritical marks indicating that something (maybe the same story, maybe something else) has been omitted. Augustine, in fact, aware of the story’s absence from many texts of the Gospel, opined that perhaps it had been removed because of the offense it might give to pious souls unable to understand how Christ could excuse so grave a transgression with no more than an exhortation to sin no more.
It seems that the story was something of a freely floating tradition, perhaps with very deep roots in Christian memory, one that was not originally firmly associated with any particular Gospel text, but that was inserted in various versions of Luke or John because it was too beautiful and too illuminating of Christ’s ministry and person to be left out of the church’s lectionary cycle (and hence out of scriptures).
—David Bentley Hart, The New Testament: A Translation. Yale University Press, 2017, pp. 187–188. My added paragraph breaks.
Marks in the manuscripts showing something missing at that point? Some fascinating possibilities there.