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 11:1On title, see Introduction. Alluding to some event in his history, as in Sa1 23:13, the Psalmist avows his confidence in God, when admonished to flee from his raging persecutors, whose destruction of the usual foundations of safety rendered all his efforts useless. The grounds of his confidence are God's supreme dominion, His watchful care of His people, His hatred to the wicked and judgments on them, and His love for righteousness and the righteous. (Psa 11:1-7)
my soul--me (Psa 3:2).
Flee--literally, "flee ye"; that is, he and his companion.
as a bird to your mountain--having as such no safety but in flight (compare Sa1 26:20; Lam 3:52).
psa 11:2privily--literally, "in darkness," treacherously.
psa 11:3Literally, "The foundations (that is, of good order and law) will be destroyed, what has the righteous done (to sustain them)?" All his efforts have failed.
psa 11:4temple . . . heaven--The connection seems to denote God's heavenly residence; the term used is taken from the place of His visible earthly abode (Psa 2:6; Psa 3:4; Psa 5:7). Thence He inspects men with close scrutiny.
psa 11:5The trial of the righteous results in their approval, as it is contrasted with God's hatred to the wicked.
psa 11:6Their punishment is described by vivid figures denoting abundant, sudden, furious, and utter destruction (compare Gen 19:24; Job 18:15; Psa 7:15; Psa 9:15).
cup--is a frequent figure for God's favor or wrath (Psa 16:5; Psa 23:5; Mat 20:22-23).
psa 11:7his countenance--literally, "their faces," a use of the plural applied to God, as in Gen 1:26; Gen 3:22; Gen 11:7; Isa 6:8, &c., denoting the fulness of His perfections, or more probably originating in a reference to the trinity of persons. "Faces" is used as "eyes" (Psa 11:4), expressing here God's complacency towards the upright (compare Psa 34:15-16).