Charles H. Spurgeon on Psalms 106:13

They soon forgat. As it is with a sieve or boulter, the good corn and fine flour goes through, but the light chaff and coarse bran remains behind; or as a strainer, that the sweet liquor is strained out, but the dregs are left behind: or as a grate, that lets the pure water run away, but if there be any straws, sticks, mud, or filth, that it holds. Thus it is with most men's memories; by nature they are but, as it were, pertusa dolia, mere river tubs, especially in good things very treacherous, so that the vain conceits of men are apt to be held in, when divine instructions and gracious promises run through; trifles and toys, and worldly things, they are apt to remember, tenacious enough; but for spiritual things they leak out; like Israel, they soon forget them. William Gouge.