Verse 3 repeats essentially the thought of verse 2. The verb translated searchest out comes from a root, found only here in the Old Testament, meaning “to measure off, determine” (see K-B, Holladay). In verse 3a my path and my lying down is parallel with all my ways in verse 3b and means all activities, one’s “entire life” (Anderson). New Jerusalem Bible translates “when I walk or lie down,” and Dahood translates “my departure and my arrival” and “all my travels.” Briggs explains the verse as follows: “the path he followed when he rose in the morning and the resting place to which he returned for the night,” while all my ways indicates everything that happened between morning and night.

Yahweh’s knowledge extends also to the psalmist’s unspoken words (verse 4); Yahweh knows what the psalmist will say even before he says it.

In verse 5a the Hebrew verb (Revised Standard Version beset) usually means “besiege” in a hostile sense; here it obviously means “surround,” but in a protective, benevolent sense. In some languages Good News Translation‘s “You are all around me” will be expressed as a simile; for example, “You are like a fence (or, hedge) that protects me.” In verse 5b “you lay your hand on me” is also used in a good sense of protection and care.

Quoted with permission from Bratcher, Robert G. and Reyburn, William D. A Handbook on the Book of Psalms. (UBS Helps for Translators). New York: UBS, 1991. For this and other handbooks for translators see here .