Passage
Answer me when I call, O God of my righteousness; Thou hast set me at large [when I was] in distress: Have mercy upon me, and hear my prayer.
Answer me when I call, O God of my righteousness; Thou hast set me at large [when I was] in distress: Have mercy upon me, and hear my prayer.
Psalms 4:1 Answer me when I call, O God of my righteousness; Thou hast set me at large [when I was] in distress: Have mercy upon me, and hear my prayer.
Psalms 4:2 O ye sons of men, how long shall my glory be turned into dishonor? [How long] will ye love vanity, and seek after falsehood? Selah
Psalms 4:3 But know that Jehovah hath set apart for himself him that is godly: Jehovah will hear when I call unto him.
The verse centers on "mercy", "answer", "call", "righteousness", "thou", "hast", "large", and "distress". It is saying that the verse draws attention to "mercy" and "answer", so its meaning should be read from those terms before moving to application.
The next verse adds "O ye sons of men how long...", so "mercy" and "answer" should be read forward into that movement. In Psalms context, the local focus is worship, trust, the LORD's kingship, and covenant mercy.
A plain takeaway is to answer the verse's own emphasis on "mercy" and "answer" with trust shaped by these words, not by a vague optimism outside the passage.