A string, rope, or cord used for measuring. (1Ki 7:15, 23; Am 7:17; Zec 2:1, 2) Some measuring lines were apparently divided into cubits. (2Ch 4:2) The extent of a particular land area was determined by stretching or casting a measuring line upon its surface. (Compare Job 38:4, 5; Ps 78:55; Mic 2:4, 5.) Builders used it, as when laying out a city (Jer 31:38, 39; Zec 1:16), and a wood carver might use it to set the dimensions of an object. (Isa 44:13) On one occasion King David appears to have measured off the vanquished Moabites that were to be put to death from those to be preserved alive.​—2Sa 8:2.

Figurative Use. In a figurative sense, “measuring line” denotes a rule, or standard, of action. (Isa 28:10, 13) For example, Jehovah made “justice the measuring line” when dealing with his unfaithful people. (Isa 28:17) His applying the same measuring line to Jerusalem as he had to Samaria pointed to a similar desolation for Jerusalem. (2Ki 21:13; La 2:8) His stretching out “the measuring line of emptiness” on Edom likewise betokened destruction, and the use of this measuring line meant apportioning the land to the animals that would begin to dwell in the desolated areas of Edom.​—Isa 34:5-17.

David regarded his relationship with Jehovah as his portion in life. This was a most satisfying inheritance, prompting him to say: “The measuring lines themselves have fallen for me in pleasant places.”​—Ps 16:5, 6; compare Nu 18:20.

The heavenly bodies testify to God’s creative activity, and since their silent testimony fills the earth, the psalmist could say respecting them: “Into all the earth their measuring line has gone out.”​—Ps 19:1-4; Ro 1:20.

See REED.