4 “If I had not lowly thoughts, but have lifted up my soul, as one taken from his mother's breast, such the reward for my soul”. He seems as it were to have bound himself by a curse:...as though he had been going to say, Let it so happen to me. “As one taken away from his mother's breast, may be my soul's reward.” You know that the Apostle says to some weak brethren, “I have fed you with milk, and not with meat; for hitherto you were not able to bear it, neither yet now are you able.” There are weak persons who are not fit for strong meat; they wish to grasp at that which they cannot receive: and if they ever do receive, or seem to themselves to receive what they have not received, they are puffed up thereby, and become proud thereupon; they seem to themselves wise men. Now this happens to all heretics; who since they were animal and carnal, by defending their depraved opinions, which they could not see to be false, were shut out of the Catholic Church....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)