Words: into and on

Matthew 5:1 And seeing the multitudes, he went up into a mountain: and when he was set, his disciples came unto him: [kjv]

ιδων δε τους οχλους ανεβη εις το ορος και καθισαντος αυτου προσηλθαν αυτω οι μαθηται αυτου [gnt]

The KJV (King James Version) translates as "into a mountain" what in the Greek is "into the mountain" (definite article) as a specific but unnamed mountain.

Going or being "επί" ≈ "on" the mountain means going (if necessary) and being "on" the mountain semi-permanently.
Going "εις" ≈ "into, to" the mountain means going "to" and "on" the mountain but only temporarily.

More: Matthew 5:1-2 Sermon on the mount audience

Matthew 5:1 And seeing the multitudes, he went up into a mountain: and when he was set, his disciples came unto him: [kjv]

ιδων δε τους οχλους ανεβη εις το ορος και καθισαντος αυτου προσηλθαν αυτω οι μαθηται αυτου [gnt]

It appears that Jesus was getting away from the crowds. Jesus had many disciples, not just the 12 remaining at the end. So the Beatitudes "teachings" are a private briefing these disciples.
Later, in John 6, Jesus starts to explain his real mission and many stop following him (for the food, healing, etc.). The 12 disciples remain.

More: Matthew 5:1-2 Sermon on the mount audience

The Greek words for "into" and "on" did not have the same meaning as English today. Consider a mountain.

Going or being "επί" ≈ "on" the mountain means having gone (if necessary) and then being "on" the mountain, perhaps semi-permanently, and, while there, being in a static state of rest.
Going "εις" ≈ "into, to" the mountain means going "to" and then "onto" the mountain but only temporarily and a dynamic state of motion.

English sayings:

... into your face ...
... into your mind ...
... tear into you ...

The ancient Greek word "ἐπί" ≈ "on, upon" as in the prefix of the English word "epicenter" which is, literally, "on the center".

Matthew 18:5 And whoso shall receive one such little child in my name receiveth me. [kjv]

και ος εαν δεξηται εν παιδιον τοιουτο επι τω ονοματι μου εμε δεχεται [gnt]

The KJV translates as "in" my "name" the Greek that it "on" the "name" of mine. The "on", as a contrast, will become important in a few verses where "on" will be translated as "into". (see below)

The ancient Greek word "ἐπί" ≈ "on, upon" as in the prefix of the English word "epicenter" which is, literally, "on the center".

The ancient Greek word "ὄνομα" ≈ "name, noun" is related to Latin "nomen" ≈ "name, noun" (semantic loan from Greek) and English "name".

One must distinguish "names" which are abstract letters combined to make a word and the "meaning" to which the word or "name" is attached. The "meaning" depends on context.

More: Equivocation deception between names and meanings

More: Matthew 18:2-11 Great children trapped in the middle

Matthew 18:5 And whoso shall receive one such little child in my name receiveth me. [kjv]

και ος εαν δεξηται εν παιδιον τοιουτο επι τω ονοματι μου εμε δεχεται [gnt]

18:12 How think ye? if a man have an hundred sheep, and one of them be gone astray, doth he not leave the ninety and nine, and goeth into the mountains, and seeketh that which is gone astray? [kjv]

τι υμιν δοκει εαν γενηται τινι ανθρωπω εκατον προβατα και πλανηθη εν εξ αυτων ουχι αφησει τα ενενηκοντα εννεα επι τα ορη και πορευθεις ζητει το πλανωμενον [gnt]

The ancient Greek word "επι" ≈ "on" as in the first part of the English word "epicenter" as "on" the "center".

In Matthew 18:5, the KJV translates as "in" my "name" the Greek that is "on" the "name" of mine.
In Matthew 18:12, the KJV translates as "into" the mountains the Greek that that is "on" the mountains.

More: Matthew 18:12-14 Sheep astray on a mountain of definitions

Matthew 5:23 Therefore if thou bring thy gift to the altar, and there rememberest that thy brother hath ought against thee; [kjv]

εαν ουν προσφερης το δωρον σου επι το θυσιαστηριον κακει μνησθης οτι ο αδελφος σου εχει τι κατα σου [gnt]

The Greek translated as "bring" is that of "offering" or, literally, "carry to". The ancient Greek word "προσφέρω" ≈ "bring to or upon, apply to, lay upon".
The Greek translated as "to" is that of "on" or "onto". The ancient Greek prefix "επι" ≈ "on" as in the English word "epicenter" which is, literally, "on the center".

That is, you are "carrying to (offer)" your "gift" "on" the "altar".

Paraphrase: if therefore you shall offer (carry forward) your gift on (onto) the altar ...

The modern Greek word "προσφέρω" (pro-SFEH-ro) ≈ "offer".

More: Matthew 5:23-24 Alterated gifts

The ancient Greek word "εις" ≈ "into, to".

There is similar Greek word spelled with the same letters that would have been pronounced somewhat differently: "εἷς" ≈ "one".

Matthew 24:16 Then let them which be in Judaea flee into the mountains: [kjv]

τοτε οι εν τη ιουδαια φευγετωσαν εις τα ορη [gnt]

24:17 Let him which is on the housetop not come down to take any thing out of his house: [kjv]

ο επι του δωματος μη καταβατω αραι τα εκ της οικιας αυτου [gnt]

This verse sequence is part of the Olivet Discourse where Jesus talks about "all of it" and the "end of times" and appears to refer to an actual "mountain". It is not clear how one would flee to a "definition".

The ancient Greek word "εις" ≈ "into" (more active and dynamic).
The ancient Greek word "επί" ≈ "on" (more passive and static)

It is unclear how one would flee "into" the "mountains" rather than "on" the "mountains" (some Greek manuscripts)

What is often attributed to Koine Greek idioms appears to be a bias as to what the translators (and Greek scholars) want the text to say - often made worse by changes in the English language over time.

More: Matthew 24:37-39 Days of Noah

More: Delimiting the boundary of the region of a mountain

Matthew 18:12 How think ye? if a man have an hundred sheep, and one of them be gone astray, doth he not leave the ninety and nine, and goeth into the mountains, and seeketh that which is gone astray? [kjv]

The GNT (Greek New Testament) has "επί" ≈ "on" the "mountains" or "definitions". The word "εις" ≈ "into" is not used here.
Why does the "man" need to go "on" the "mountains" to "seek" and "find" the "sheep"? This is in contrast to "into" the "mountains".

How many sheep did the engineer have?

The engineer started with 99 sheep but when he rounded them up, it was 100. [counting sheep]

More: Matthew 5:13-16 Animal crackers

More: Matthew 18:12-14 Sheep astray on a mountain of definitions

Matthew 10:9 Provide neither gold, nor silver, nor brass in your purses, [kjv]

μη κτησησθε χρυσον μηδε αργυρον μηδε χαλκον εις τας ζωνας υμων [gnt]

… possidere aurum … argentum … pecuniam in zonis … [v]

The ancient Greek word "εἰς" ≈ "into" and is the opposite of the ancient Greek word "εξ" ≈ "out of" as in "Exodus" as "the way out".

The ancient Greek word "ἐν" ≈ "in, on, at".

The KJV translates as "purse" The ancient Greek word "ζωνη" ≈ "belt, sash" which is the source of the English word "zone".

What does this verse mean? This guideline does not appear to ever have been rescinded.

More: Matthew 10:5-10 Possessing acquired purchases

1 Thessalonians 4:10 And indeed ye do it toward all the brethren which are in all Macedonia: but we beseech you, brethren, that ye increase more and more; [kjv]

και γαρ ποιειτε αυτο εις παντας τους αδελφους τους εν ολη τη μακεδονια παρακαλουμεν δε υμας αδελφοι περισσευειν μαλλον [gnt]

The Greek for "toward" is the ancient Greek word "εις" ≈ "into".Paul will use the ancient Greek word "πρός" ≈ "to, towards" in verse 12.
The Greek for "more and more" is that of "rather" as a comparison.
The Greek for "beseech" is that of "pleading" as in "please". and is related to the word for "Paraclete" as in the "helper" or "Holy Spirit". This was translated as "exhort" in verse 1.

More: 1 Thessalonians 4:1-18 Caught up in the rapture

Matthew 24:13 But he that shall endure unto the end, the same shall be saved. [kjv]

ο δε υπομεινας εις τελος ουτος σωθησεται [gnt]

The ancient Greek word "τέλος" ≈ "end, purpose, complete". The ancient Greek word "εις" ≈ "into".

Paraphrase: But he that shall endure into the purpose, the same shall be saved.

That is, one does not need to endure to the "end" of time or "end" of the age or "end" of life. One needs to endure "into" the "purpose". To do that, one needs to insure that one knows the correct "goal" or "purpose" "into" which to "endure".

The "purpose" is similar to the idea of a "goal" or "postcondition" or "result" of "running" the "code" with "data" in computer science.

The Greek word for "endure" is sometimes translated as "patient" and is related to the word for "abide" or "remain".

More: John 1:1-5 Four causes in a design and implementation model