Ecclesiastes 11:2; Ecclesiastes 11:5-6; Ecclesiastes 11:8-9

2 Give a portion to seven, or even to eight, for you know not what evil may happen on earth.
5 As you do not know how the spirit comes to the bones in the womb of a woman with child, so you do not know the work of God who makes everything. 6 In the morning sow your seed, and at evening withhold not your hand; for you do not know which will prosper, this or that, or whether both alike will be good.
8 For if a man lives many years, let him rejoice in them all; but let him remember that the days of darkness will be many. All that comes is vanity. 9 Rejoice, O young man, in your youth, and let your heart cheer you in the days of your youth; walk in the ways of your heart and the sight of your eyes. But know that for all these things God will bring you into judgment.