John Gill Commentary Psalms 37:13

"The Lord will laugh at him; For he seeth that his day is coming." — Psalms 37:13 (ASV)

The Lord shall laugh at him
Have him and his plots in derision, confound his schemes, and disappoint him of his designs, bring him into calamity, and laugh at it; see (Psalms 2:4) (Proverbs 1:26) ;

for he sees that his day is coming ;
either the day of the Lord, which he has appointed to judge the world in, and which comes suddenly, at unawares, as a thief in the night, and is known unto the Lord, though to none else; or the day of the wicked man's ruin and destruction, to which he is appointed, and which is the same; and so the Targum is, "the day of his calamity": which the Lord observes is hastening on, when he will be for ever miserable.