They that observe lying vanities. — See Note, Psalms 31:6.
Forsake their own mercy — i.e., forfeit their own share of the covenant grace. In Psalms 37:28 it is said that Jehovah does not forsake his chasîdim; they, however, by forsaking Jehovah (Himself called Israel’s mercy, Psalms 144:2, margin) and His law (Psalms 89:30) can forfeit their chesed or covenant privilege.