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. — Comp. “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.”