Could you explain what it means in
Ecclesiastes 11:1-2 when it says to "cast your bread upon the waters?
Response: A rather literal rendering of the Hebrew of Ecclesiastes 11:1-2 says, "Send your substance [out] over the face of the water [i.e., the sea] that you may find it [again] many days hence. Give a share to seven, or even to eight, for you cannot know what [sort of] disaster may come upon the land."
These verses are speaking about "not putting all one's eggs in one basket", but doing so from a more sophisticated managerial point of view. The "sending forth of substance" is, I believe, referring to investment of accumulated wealth. The options in ancient Israel were limited. Hoarding had its dangers; expansion of agriculture was difficult and spiritually questionable given that this may have deprived others of their inheritance (even if done with legal means); but foreign trade, directly or through underwriting, would have been a prudent way to preserve capital in a spiritually acceptable way (after all, loaning money at interest to fellow Israelites was not something which God was pleased, but it was permitted where foreigners were concerned: Deut.23:19-20).
The phrase "give portions to seven/eight" likewise refers to prudent and careful investment of excess capital or means of production. In the ancient Greek economy, for example, we know that it was not uncommon for men of some substance (i.e., not under the direct and dire necessity of doing just whatever they could, but with at least some options) to farm/manage/own multiple plots of ground in slightly different areas. This is a different approach from what we see in the Midwest of the U.S. (and elsewhere), where the tendency has been to consolidate holdings (and expand them) rather than to diversify. In ancient Greece, layered diversification of this sort was a hedge against disaster. The odds were that at least one of the geographical areas or one of the crop types would do well enough, even if the majority did not, so that one would have at least some income, at least some success. Olives might have a bad year, but grapes might do well; wheat might be marginal, but barley might yield a bumper crop (and so on). In addition to the difference in the types of crops, the rainfall in Greece varies considerable almost from hillside to hillside (i.e., far more variable than what we normally experience here in the USA), so that this practice of a "mosaic" approach to agriculture was the rule on the mainland in many places. We know less about the agricultural practices of ancient Israel, but what is said about royal lands indicates to me that someone like Solomon (and others of means) would have taken the approach we call in modern investment of "diversification". If a man of some means took this approach (directly or by backing a variety of other projects) he could potentially reduce risk while at the same time avoiding the exploitation of other Israelites. Therefore the command to divide portions seven or eight ways is a call to careful, prudent stewardship of whatever may be under one's charge (as opposed to unnecessary risk-taking).
But this is only part of the story, of course. The message to be gained from these verses is really not so much "here's how to invest and make money", but rather "don't set your heart on riches, for everything in this world is uncertain". Most of us do not have any "excess capital" laying around, let alone enough to make it worthwhile to ship it off to seven or eight different places. This was certainly true of most of Solomon's original audience as well. In the history of the family of God, the privileged have been few (Matt.10:25; cf. 1Cor.1:26). No, these verses are first and foremost meant to produce a sense of humility in the face of life's uncertainty. We who live from day to day (or more or less so) put our trust in the Lord. But those who have an excess of worldly means are subtly reminded here by Solomon that worldly wealth is in fact a very uncertain thing, even if the ephemeral nature of worldly riches is often blindly ignored by most of those who possess them for a time. Consider these teachings of scripture on the subject (extract from part 4 of the Satanic Rebellion series, "Greed"):
1) You cannot truly give your allegiance to God while at the same time trusting in and lusting after material gain - you can't worship both God and "Mammon" at the same time (Matt.6:24; Lk.16:13).
2) We brought nothing into this world and will take nothing out of it (1Tim.6:7-8).
3) Lust for material gain makes us vulnerable to the devil's attacks, and threatens our salvation (1Tim.6:9).
4) The love of money is a source of all sorts of evils, turning us from the faith and causing us much anguish (1Tim.6:10).
5) Greed is essentially idolatry (Col.3:5), and its practitioners idolaters (Eph.5:5).
6) Covetousness lured Balaam into sacrificing his relationship with God for the sake of money, so that his actions are proverbial for the deceptiveness of wealth (2Pet.2:15; Jude 11).
7) Envy is the true root of acquisition lust (Eccl.4:4).
8) The lust for wealth can never be satisfied by any success (Eccl.5:10).
9) Wealth can be a severe disadvantage, keeping us from God (Lk.18:23-25).
10) Where your treasure is, there is your heart also (Matt.6:19-21; cf. Lk.12:32-34).
11) What does it profit a man to gain the world but lose his life? (Mk.8:36; Lk.9:25)
12) Your life does not depend upon an abundance of possessions (Lk.12:15).
13) Storing up material things rather than striving to be rich towards God is folly (Lk.12:21).
14) Discipleship requires the willingness to put God before possessions (Lk.14:33).
15) Wealth can distort one's perspective, choking spiritual growth (Mk.4:19).
16) Nothing is permanent, not even great wealth; great wealth merely subjects the possessor to greater temptation and a higher standard of judgment (Jas.5:1-6 and Lk.12:48).
17) Covetousness is forbidden by the 10th commandment (Ex.20:17; Deut.5:21).
Thus the proper attitude for all who have been blessed with worldly wealth is not to put their faith in it or to assume that these riches will continue to grow and be secure (even if split into seven or eight portions to hedge against disaster), but rather to do as James counsels and make one's plans subject to "the Lord [being] willing" (Jas.4:13-17), to humbly act and humbly think, remembering that this world and its wealth last but a moment, but that our treasures in heaven will last for all eternity ((Matt.6:19-21).
Please see also the following links:
Eternal Rewards (in CT 6)
Strangers in the Devil's Realm (in SR 4)
Yours in the One who made Himself poor that we might be rich forever, the One who always keeps our true deposit safe and secure in heaven above, our Lord Jesus Christ.