Ecclesiastes 11:4-6

4 He who observes the wind won't sow;  And he who regards the clouds won't reap.

5 As you don't know what is the way of the wind,  Nor how the bones grow in the womb of her who is with child;  Even so you don't know the work of God who does all.

6 In the morning sow your seed,  And in the evening don't withhold your hand;  For you don't know which will prosper, whether this or that,  Or whether they both will be equally good.