Adam Clarke on Psalms 27:7

Hear, O Lord, when I cry - This is the utmost that any man of common sense can expect - to be heard when he cries. But there are multitudes who suppose God will bless them whether they cry or not; and there are others and not a few, who although they listlessly pray and cry not, yet imagine God must and will hear them! God will answer them that pray and cry; those who do not are most likely to be without the blessings which they so much need.