A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
psa 142:1Maschil--(See on Psa 32:1, title). When he was in the cave--either of Adullam (Sa1 22:1), or En-gedi (Sa1 24:3). This does not mean that the Psalm was composed in the cave, but that the precarious mode of life, of which his refuge in caves was a striking illustration, occasioned the complaint, which constitutes the first part of the Psalm and furnishes the reason for the prayer with which it concludes, and which, as the prominent characteristic, gives its name. (Psa 142:1-7)
with my voice--audibly, because earnestly.
psa 142:2(Compare Psa 62:8).
I poured out my complaint--or, "a sad musing."
psa 142:3thou knewest . . . path--The appeal is indicative of conscious innocence; knowest it to be right, and that my affliction is owing to the snares of enemies, and is not deserved (compare Psa 42:4; Psa 61:2).
psa 142:4Utter desolation is meant.
right hand--the place of a protector (Psa 110:5).
cared for--literally, "sought after," to do good.
psa 142:5(Compare Psa 31:14; Psa 62:7).
psa 142:6(Compare Psa 17:1).
psa 142:7(Compare Psa 25:17).
that I may praise--literally, "for praising," or, "that Thy name may be praised," that is, by the righteous, who shall surround me with sympathizing joy (Psa 35:27).