GENESIS 2:10
 

[NKJV]

Now a river went out of Eden to water the garden, and from there it parted and became four riverheads.
 

[BSB]

Now a river flowed out of Eden to water the garden, and from there it branched into four headwaters:

Though the Garden received many things directly from the heaven above where God dwelt, rain or showers (watering) from heaven was not one of them. Remember the earth had learnt to water herself instead of waiting for God to cause it to rain from heaven: 

*1.* A Mist "Went-up" (against Gravity) to water the whole face of the ground according to "Genesis 2:6" and,

*2.* A River "Went-out" (against Self-centeredness) to water the Garden according to this Bible verse above.

Now, looking carefully at these waters or rivers in "Genesis 2" you should note that the scriptures animated the waters in this chapter, making the waters/rivers to appear like independent living creatures that acted on their own without being caused or made to act as they acted by God. The only time anything pertaining to water was imputed to God in "Genesis 2" was when it was said "God had not caused it to rain," and with that everything about River or watering was not imputed or credited to what God did until when God caused it to rain in "Genesis 7."

Yes, we know God is the One doing all things even in secrets, but let's follow how it appeared in the Bible. You see when talking about the plants or trees in "Genesis 2," the scriptures imputed it to God as He who made or caused it in "Genesis 2." When talking about the people and living creatures in "Genesis 2," the scriptures imputed it to God as He who made or caused it in "Genesis 2." However, when talking about the water and watering in "Genesis 2," the Bible did not imput it to God as He who made or caused it in "Genesis 2" just as the Spirit of God moved in "Genesis 1." So let's assume the waters in "Genesis 2" had mind of their own, and acted or moved by their self motivation and will.

In the Bible verse above,

A River went-out of Eden to water the Garden, 

Nothing was said about how the River emerged or came in Eden in the first place, not even to mention the source of the River. We only know the River was there when the River was going out of Eden with the purpose of watering the Garden.

That was the "First River" from the beginning in Genesis, and so was the beginning of how Rivers on earth may become. This River was not a Collector, but a Distributor. The River was a selfless Giver, who was not only giving (watering) but was also reaching out or doing outreaches in order to give or distribute more to other parts of the earth after covering the Garden of Eden first. 

It was not the Garden of Eden that gave to the River, rather the River was the one giving to the Garden of Eden and giving to various lands and places in various parts of the earth. So that River was technically, "A Minister of God" to the Garden and to all it watered (ministered drinks to).

When it seemed all attention of the heavens and the world were focused only on the Garden, the River was busy traveling to other parts of the world that were not attractive and making those places attractive and well watered. The River was taking the Gospel and reaching out with the Gospel both within the congregation of the Garden of Eden and far beyond in other uttermost parts of the earth with just four heads or branches. So even if the Lord would not cause it to rain for some time more, this River or Stream Movement would be doing for the earth what the rain was not yet doing.

And from there the River parted and became four heads

Was the River not supposed to diminish the more the grounds and creatures drank or took from it? Was the River not supposed to dry up during the dry season when there's no rain? 

Why or how comes the River was growing mightier and greater the more the River watered or distributed its resources to feed the thirsty? How did the little River grew into four mighty River-Heads and Branches, that became the greatest Rivers in the entire history of the earth even to the point that no draught or dry season could dry one of those River Head called "Euphrates" until the sixth Angel pours his vial of God's wrath on the River Euphrates to dry it in the end times according to "Revelation 16:12?"

The River from Eden was watering all things, the more the River was being watered and increasing, so that being more liberal or generous in giving and reaching out was making the River fatter and richer. As it is written,

[Proverbs 11:24‭-‬25 NKJV] — There is one who scatters, yet increases more; And there is one who withholds more than is right, But it leads to poverty. The generous soul will be made rich, And he who waters will also be watered himself.

It's like the River from the Temple of God in the days to come, as shown to Ezekiel in "Ezekiel 47." The more the water from the Temple or House of God was advancing from the House to reach out to people and creatures in the world with the Gospel from the House of God in outreaches, the more greater in size the capacity of that River became until the River grew into a size that a man could not swim and cross through. That's where the river have reached the remotest and farest points to the world, far away from the house or church temple where the gospel or water was coming from.

This is a secret to growing in grace and in anointing of the Holy Spirit, reaching out and giving out in abundance freely, beyond your church or garden into those outside the christian circle, even to those who have nothing to do with God, bringing the gospel, the grace and the light to them, and then watch as yours are increasing more and more the further you get outside your church or brethren community with your gospel. 

Not the gospel of inviting them to your church before they can drink, but the gospel of taking the drink to them there where they are. Like these waters or rivers did not invite the world or Creatures out there to come to the garden or to the house of God before they drink; rather they gave them the drinks wherever they met them, just as Melchizedek was a Priest moving about with holy Communion and administering Holy Communion to those He had to do so to, wherever He met them on the Streets, without necessarily bringing them to any church or temple before he would feed them the blessings and communion of bread and wine. 

These were Outreaches and Liberality in distribution of Grace. Stop sharing the Grace of our Lord Jesus Christ only when you are in church or within your fellow church members or Christians. Get to sharing the Grace of our Lord Jesus Christ, the love of God, and fellowship of the Holy Spirit, with those far away from your church or house of God. Go into all the world with the Gospel.