Set a guard, O LORD, over my mouth; keep watch over the door of my lips!
PSALM 141 Whatever may have been the immediate cause pressing David to pray in the manner he does in this Psalm, Many commentators are strongly of opinion, that this Psalm was written as a memorial of that very interesting scene in the life of David, recorded in 1 Samuel 24, relating to his generous treatment of Saul.
Commenting on Psalm 141:1-10
Set a watch, O Lord, before my mouth. That mouth had been used in prayer, it would be a pity it should ever be defiled with untruth, or pride, or wrath; yet so it will become unless carefully watched, for these intruders are ever lurking about the door.
Mercy to accept what we do well, and grace to keep us from doing ill, are the two things which we are here taught by David's example to pray to God for. I. David loved prayer, and he begs of God that his prayers might be heard and answered, Psa 141:1, Psa 141:2. David cried unto God. His crying denotes fervency in prayer; he prayed as one in earnest.
Commenting on Psalm 141:1-4