What does it mean for someone to be another person's “portion”?

Question

Searching for the word "portion" brings up a lot of results in the Bible. Sometimes it means a portion of food or of money. But what exactly does it mean in the following context:

LORD, you alone are my portion and my cup; you make my lot secure. -Psalm 16:5

My flesh and my heart may fail, but God is the strength of my heart and my portion forever. -Psalm 73:26

You are my portion, LORD; I have promised to obey your words. -Psalm 119:57

I cry to you, LORD; I say, “You are my refuge, my portion in the land of the living.” -Psalm 142:5

The idols among the smooth stones of the ravines are your portion; indeed, they are your lot. -Isaiah 57:6

“Let me inherit a double portion of your spirit,” Elisha replied. -2 Kings 2:9

“To you I will give the land of Canaan as the portion you will inherit.” - 1 Chronicles 16:18

He who is the Portion of Jacob is not like these, for he is the Maker of all things, including the people of his inheritance—the LORD Almighty is his name. -Jeremiah 51:19

The LORD will inherit Judah as his portion in the holy land and will again choose Jerusalem. -Zechariah 2:12

(All verses are from the NASB.)

The list goes on, but I wanted to show how often it was used. Repetition can sometimes imply significance.

What I'm getting out of this is that the Lord is our portion and we are his portion. What does this mean?

Answer 1

A good synonym here would be "inheritance," aka, a portion of that which we will be given when we / as we inherit the Kingdom.

Answer 2

I'm going to focus on just one example and assume that it will cover many of the other examples. If you find a reference that doesn't quite fit, let me know in the comments and I'll see if I can address it.

Psalm 16:5-6 (ESV) reads:

The LORD is my chosen portion and my cup;
    you hold my lot.
The lines have fallen for me in pleasant places;
    indeed, I have a beautiful inheritance.

The first thing to notice is that in Hebrew poetry, ideas are often repeated several times using different phrasing or imagery. Modern English Bibles often group these related lines together in stanzas as the ESV does above. In this case, the same image of dividing up the inheritance of property, is repeated four time. The last line actually uses the word "inheritance" and emphasizes that it is a good one.

Working backwards, the third line talks about how the author's metaphorical property lines have been especially beneficial. This sounds strange in our culture, but to the ancient Hebrews the analogy was perfectly clear for when an inheritance was received by several brothers, the allocation was done by lot. There are many examples in the Bible of people using lots to divide property.

In fact the second line references that practice and suggests that God played a part in the process. Once again, this isn't as odd as it seems to us in our hyper-rational culture. We use random selection methods primarily for playing games, but in other cultures divination of this sort was often used to query the gods. Israel had an institutional form of cleromancy in the Urim and Thummim.

Moving back to the end of the first line, the author compares the LORD to "my chosen portion" and "my cup". In passing, Joseph mentioned that he used a silver cup for divination. It's possible, the cup is connected to the lot of the second line. More likely, it's a callback to verse 4. But by parallels in the rest of the stanza, the meaning of "portion" here is clear: the psalmist is asserting that God belongs to him because of his identity as a son of Israel.

Summary

A quick look at the examples you've provided reveals that, in each case, the word "inheritance" can be substituted for the "portion". In keeping with the general outline of Genesis, it points to God's process of choosing one group of people out of all the nations to be His own. Therefore, God's people also have a unique claim on Him.

Answer 3

Part of the confusion you have is that there are two different Hebrew words translated as "portion", both of which are taking the same idiomatic usage.

The first is "mana". This does not in any way mean "inheritence", it is very much like the idiomatic French word "coup", as in "coup de grace", "coup de main". It shows up in many Hebrew contexts, with the general meaning of "serving", "portion", "helping", "my share", "my allotment", etc. It is the "can" in "I will open a can of whoop-ass", or the boatload in "You will be in a boatload of trouble". It's just a generic quantity word.

The word is related in root to "Mann" (Manna), a helping of God's food in the desert, although the folk-etymology of "Mann" in Exodus is a well preserved actual ancient joke: the Hebrews, when they first see it, say "Mann-Hu?" meaning "What's that?" in Aramaic tinged Hebrew. But "Mann hu!" means "This is Mann!", with the same words, but as a statement instead of a question. The etymology is completely anacronistic, but in Hebrew, it's genuinely funny (smile funny, not LOL funny), and its falsehood is part of what makes it so funny. One of the problems with Biblical literalism is that a lighthearted play on words like this is turned into deadly serious history, with absurd results. This is a disservice to the text.

The word "Mana" is also related to counting, and to sorting. This is why nearly all translators settle on "portion" for the translation, because this is related to "apportion" with similar financial connotations.

The word mana is not in any way in the future, like an inheritance or "nachala" is, the roots are not related. Inheritance is also far too specific. The word just means "my due" (which you might think would be a better English translation choice, except that it's short for "my due portion" in English, so it's no good).

The meaning of "Mana" in the Psalms is the idiomatic meaning of "my due part", so that it reads "Yahweh, you are the portion of my division, of my cup", but it might also be a dropped letter or vowel for "Yahweh, you have counted out my division, my cup". Both readings are supportable.

In the later psalms, the word for "portion" is "chelki" (my part). This is the other word used in this manner. In 119:57, you can also read it as "My task, Yahweh, is to keep your commandments", rather than "My part is Yahweh. I will keep your commandments." But the other psalms are unambiguous-- Yahweh is the "chelki". It's more of a statement of duty, as in "this is my fate. Yahweh!" It's a nice sentiment, which carries connotations of duty and faith, but no connotations of future reward.