My understanding of these sorts of things is that Jesus was true man, speaking to other people in their time and place. He speaks colloquially, in a way understandable to everyone of his time and place…
I agree, and there are ways to show the point from scripture; This particular expression is a prophecy, and one of very specific historical significance.
Matthew 12:40
usccb.org/bible/matthew/12
Many recordings of it, when interpreted by colloquial ears… reduce it to just “three days”: Mark 8:31, Matthew 26:61, Matthew 27:40
And many recordings of it are very clear, that the fullness of three days is the
maximum period for the feat to be accomplished; not the minimum: Some people demonstrate that the event happening in mere hours would be sufficient as well; before ever he died.
Mark 14:58; Mark 15:29
usccb.org/bible/matthew/14
Many people misinterpreted the significance of the saying;
John 2:19, 2:20 and 21 – “But the temple he spoke of was his body.”
Ultimately, the precise meaning of the statement is based on the prophecy of Jonah – and an acting out of that prophecy in “likeness” (not exactness. Matthew 12:40)
Since we have less information on Jonah, than we do on Jesus – it’s difficult to assign a precise meaning to “three days and nights.”; as I noted above, given Jewish days start at evening – the expression introduces an ambiguity in its own right, if taken literally.
But – I can make a definite, generalized statement – about periods of three days; They are found throughout scripture as part of tests or tasks where an immediate judgment is required – and potent prayer is needed. The number three, is a number of sufficient witness and power. “Where two or three are gathered in my name there am I in there midsts”, “let a man be put to death on the word of two or three witnesses.”;
The number “three” is generally understood to be necessary only in order to break a “tie” or deadlock.
It is in this legal vein, that we often find the idea of two or three, where “two” is clearly “good enough” or even better – should things work out early.
Take Esther 4:16, where she asks for people to pray for her for three days; night and day (night listed first)…
If the endeavor were somehow to succeed before then, without her entering the room of Judgment – she would clearly be content; On the other hand, traditional rabbinical interpretation (from targums & Aben Ezra) is that her words (three days, night and day) meant prayer for “two” days, with the event itself happening during the third day.
Or again, in the book of Jonah; where the Exact wording and meaning of the event Jesus talks about is preserved; We are told that Jonas’ task is to preach (intense prayer) to Nineveh a city of “three days Journey”; Jonah 3:3
usccb.org/bible/jonah/3
And Jonah himself, had only gone ONE day’s journey before repentance
Happened; and no more need existed for him to preach – at which point, Jonah leaves the city angry to watch what will happen, and God spends two days preaching to him through a worm and a plant.
Just so, Jonah’s sign is divided into two parts – one where he is a dead man praying in the dark, and one where he preaches but for a single day.
It’s the latter preaching aspect of Jonah’s sign, that St. Peter tells us Jesus went to do after his death; 1Peter 3:19
So, that it’s hardly surprising that Jesus stayed in the grave for a little over one chronological day/time period. The task was simply completed quickly in likeness to Jonah.
Again, in scripture, we are told “Jesus rose ON the third day” and other places say “he rose after three days”; which shows that people understood both sayings to have the same meaning in spite of an apparent ambiguity.