Set a watch, O LORD, before my mouth; keep the door of my lips.

Matthew Henry's Concise Commentary

141:1-4 Make haste unto me. Those that know how to value God's gracious presence, will be the more fervent in their prayers. When presented through the sacrifice and intercession of the Saviour, they will be as acceptable to God as the daily sacrifices and burnings of incense were of old. Prayer is a spiritual sacrifice, it is the offering up the soul and its best affections. Good men know the evil of tongue sins. When enemies are provoking, we are in danger of speaking unadvisedly. While we live in an evil world, and have such evil hearts, we have need to pray that we may neither be drawn nor driven to do any thing sinful. Sinners pretend to find dainties in sin; but those that consider how soon sin will turn into bitterness, will dread such dainties, and pray to God to take them out of their sight, and by his grace to turn their hearts against them. Good men pray against the sweets of sin.