10 “If I walk in the midst of tribulation, You shall revive me”. True it is: whatsoever tribulation you are in, confess, call on Him; He frees you, He revives you....Love the other life, and you shall see that this life is tribulation, whatever prosperity it shine with, whatever delights it abound and overflow with; since not yet have we that joy most safe and free from all temptation, which God reserves for us in the end, without doubt it is tribulation. Let us understand then what tribulation he means here too, brethren. Not as though he said, “If perchance there shall any tribulation have befallen me, You shall free me therefrom.” But how says he? “If I walk,” etc.; that is, otherwise You will not revive me, unless I walk in the midst of tribulation.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)