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 61:1Neginah--or, Neginoth (see on Psa 4:1, title). Separated from his usual spiritual privileges, perhaps by Absalom's rebellion, the Psalmist prays for divine aid, and, in view of past mercies, with great confidence of being heard. (Psa 61:1-8)
From the end--that is, places remote from the sanctuary (Deu 28:64).
psa 61:2heart is overwhelmed--literally, "covered over with darkness," or, "distress."
to the rock-- (Psa 18:2; Psa 40:2).
higher than I--which otherwise I cannot ascend.
psa 61:3shelter . . . and strong tower--repeat the same sentiment.
psa 61:4I will abide--So I desire to do (compare Psa 23:6).
trust in the covert, &c.--make my refuge, in the shadow (compare Psa 17:8; Psa 36:7).
psa 61:5the heritage--or, part in the spiritual blessings of Israel (Psa 21:2-4).
psa 61:6the king--himself and his royal line ending in Christ. Mercy and truth personified, as in Psa 40:11; Psa 57:3.
psa 61:7abide before God--literally, "sit as a king in God's presence," under His protection.
psa 61:8Thus for new blessings will new vows of praise ever be paid.