Psalm 73:13 Meaning

11And they say, How doth God know? and is there knowledge in the most High?

12Behold, these are the ungodly, who prosper in the world; they increase in riches.

13Verily I have cleansed my heart in vain, and washed my hands in innocency.

14For all the day long have I been plagued, and chastened every morning.

15If I say, I will speak thus; behold, I should offend against the generation of thy children.