Charles Ellicott Commentary Psalms 141:3

"Set a watch, O Jehovah, before my mouth; Keep the door of my lips." — Psalms 141:3 (ASV)

Watch. —The image drawn from the guard set at city gates at night seems to indicate the evening as the time of composition of the psalm.

Door of my lips. —Compare doors of thy mouth (Micah 7:5), and so in Euripides, πύλαι στόματος. For the probable motive of the prayer, see Introduction. The poet’s feeling is that of Xenocrates: “I have often repented of having spoken, but never of having been silent.”