(12) I know.--Literally, I knew: i.e., I came to know. The writer is relating the conclusions at which he successively arrived.

To do good.--This phrase is always used elsewhere in a moral sense: "to act rightly." When enjoyment is meant, the phrase used is, as in the next verse, "to see good;" but the context seems to require that this sense should be given to the phrase in this verse also.

Verse 12. - I know that there is no good in them, but for a man to rejoice; rather, I knew, perceived, that there was no good for them; i.e. for men. From the facts adduced, Koheleth learned this practical result - that man had nothing in his own power (see on Ecclesiastes 2:24) which would conduce to his happiness, but to make the best of life such as he finds it. Vulgate, Cognovi quod non esset melius nisi laetari. To do good in his life; Τοῦ ποιεῖν ἀγαθόν; (Septuagint); Facere bene (Vulgate). This has been taken by many in the sense of "doing one's self good, prospering, enjoying one's self." like the Greek εϋ πράττειν, and therefore nearly equivalent to "rejoice" in the former part of the verse. But the expression is best taken here, as when it occurs elsewhere (e.g. Ecclesiastes 7:20), in a moral sense, and it thus teaches the great truth that virtue is essential to happiness, that to "trust in the Lord... to depart from evil, and to do good" (Psalm 36:3, 27), will bring peace and content (see in the epilogue, Ecclesiastes 12:13, 14). There is no Epicureanism in this verse; the enjoyment spoken of is not licentiousness, but a happy appreciation of the innocent pleasures which the love of God offers to those who live in accordance with the laws of their higher nature.

3:11-15 Every thing is as God made it; not as it appears to us. We have the world so much in our hearts, are so taken up with thoughts and cares of worldly things, that we have neither time nor spirit to see God's hand in them. The world has not only gained possession of the heart, but has formed thoughts against the beauty of God's works. We mistake if we think we were born for ourselves; no, it is our business to do good in this life, which is short and uncertain; we have but little time to be doing good, therefore we should redeem time. Satisfaction with Divine Providence, is having faith that all things work together for good to them that love him. God doeth all, that men should fear before him. The world, as it has been, is, and will be. There has no change befallen us, nor has any temptation by it taken us, but such as is common to men.I know that there is no good in them,.... In these things; as the Arabic version; in the creatures, as Jarchi; in all sublunary enjoyments; in everything the wise man had made a trial of before, as natural Wisdom and knowledge, worldly pleasure, riches, and wealth; the "summun bonum", or happiness of men, did not lie in these things; this he knew by experience, and had the strongest assurance of it: or in them, that is, the children of men, as the Targum: there is no real good thing in them, nor comes out of them, nor is done by them; they cannot think a good thought, nor do a good action, of themselves. Or rather the sense is, I know there is nothing better for them than what follows:

but for a man to rejoice; not in sin and sinful pleasures, in a riotous, voluptuous, and epicurean manner; but to be cheerful, and enjoy the blessings of life in a comfortable way, and with a thankful heart; and especially to rejoice in spiritual things, and above all in Christ; and not in any self-boastings or carnal confidences, all such rejoicing is evil; see Ecclesiastes 9:7. The Targum is,

"but that they rejoice in the joy of the law;''

but it is much better to rejoice in the things of the Gospel, which is indeed a joyful sound;

and to do good in his life: to himself and family, by making use of the good things of life, and not withholding and hoarding them up; and to others, to all men, as opportunity offers, and especially to the household of faith; and not only by liberality and alms deeds, but by doing all good works, from right principles and to right ends, and that always, as long as he lives, Galatians 6:9.