Thank you for the interpretative question on Matthew 19:9, “What does the colon in verse Matthew 19:9 in the Bible help further explain? Is it a general explanation or a situational explanation?”
The punctuation marks in our English translation of the Bible are arbitrary as the translator(s) decide best how to interpret the text or convey the meaning of the text.
The ESV’S wording of the text is this, “And I say to you: whoever divorces his wife, except for sexual immorality, and marries another, commits adultery.”[a]
The NASB’s wording of the text is this, “And I say to you, whoever [e]divorces his wife, except for [f]immorality, and marries another woman [g]commits adultery[h].”
The NIV’s wording of the text is this, “I tell you that anyone who divorces his wife, except for sexual immorality, and marries another woman commits adultery.”
The NASB-NIV Parallel New Testament in Greek and English’s wording of the text is this, “But I say to you that whoever dismisses the wife of him not of/(for) fornication and marries another, commits adultery.”
As one compares all four readings, the ESV uses the colon instead of the word, that, making it a more a direct quote as to an indirect quote. The Greek text uses the word, “oti” which is quite often translated as “that”. It appears that the translator wants to emphasis more strongly/directly the words of Jesus by substituting the word, that, with the semicolon. I don’t believe it changes the meaning of the text.
Scholars have debated the issue of divorce or no divorce for believers depending on one’s interpretation of each word and its place in the sentence structure. Generally speaking, there are no punctuation marks in the Greek as the readers in those days would understand them. For us, it is not as clear.
As I look at the context of this passage, the Pharisees bring a hypothetical situation to Jesus of whether a married man can divorce his wife for any reason at all (verse 3). Jesus answers is not situational, but a declaration that it is God’s plan that the husband and wife remain as one. Nothing was to come in between the husband and wife. He gives a definitive response in verse 9.
Scholars debate whether Jesus is saying the only exception for divorce is fornication, while other scholars interprets that not even fornication is a ground for divorce. One can read the pros and cons on the passage.
For more critical study, I would suggest a more literal translation of the text is better than an equivalent/dynamic interpretation of the text. This is one text relating to divorce or separation. There are other biblical passages that one must consider in the overall understanding on the topic of divorce and remarriage.
SUMMARY: The Pharisees bring a hypothetical situation of divorce to Jesus and Jesus’ response is a definitive one.