Adam Clarke on Psalms 36:10

O continue thy loving-kindness - Literally, "Draw out thy mercy." The allusion to the spring is still kept up.

Unto them that know thee - To them who acknowledge thee in the midst of a crooked and perverse generation.

And thy righteousness - That grace which justifies the ungodly, and sanctifies the unholy.

To the upriabt in heart - לישרי לב levishrey leb, to the straight of heart; to those who have but one end in view, and one aim to that end.

This is true of every genuine penitent, and of every true believer.