Hard - The primary meaning of the original word is permanence (compare Deuteronomy 21:4; Micah 6:2). This may be applied as here to the hard dry rock, to running streams, or to stagnant pools. In either case, the idea is that of the barren dry soil, or the impassable marsh, in contrast with the fountain of life, carrying joy and refreshment with it.
Related Commentaries of Proverbs 13:15
Proverbs 13:15
15 Good understanding giveth favour: but the way of transgressors is hard.