I have considered, if by that means I could get any comfort, the days of old, i.e. the mighty works of God done for his people in former times. Days are put for events done in them, as Psalms 37:13, Psalms 137:7 Obadiah 1:12 Micah 7:4.
Related Commentaries of Psalms 77:5
Psalms 77:5
5 I have considered the days of old, the years of ancient times.