Persons who obtain information by making secret observations. From Israel’s encampment in the Wilderness of Paran, in 1512 B.C.E., Moses sent 12 chieftains (representing all the tribes except Levi) to search out the land of Canaan. This was permitted by Jehovah at the request of the Israelites, who said: “Do let us send men ahead of us that they may search out the land for us and bring us back word concerning the way by which we should go up and the cities to which we will come.” (De 1:22, 23) Probably separating, perhaps in twos, they traveled through the land as far N as “the entering in of Hamath” and W toward the sea. (Nu 13:21; see HAMATH.) On returning, though all agreed that the land was indeed “flowing with milk and honey,” ten of the spies gave a faithless report that put fear into the Israelites. Only Joshua and Caleb encouraged them to go on into the land and take it. For Israel’s lack of faith in being influenced by the bad report, God decreed that all the men who were 20 years of age and older should die in the wilderness during an extended period of 40 years of wandering. Joshua and Caleb were excepted, and the tribe of Levi was not included.​—Nu 13:1-33; 14:6-38; De 1:24-40.

Joshua sent two spies across the Jordan to spy out Jericho in 1473 B.C.E. Rahab the harlot assisted the spies and was delivered along with her household when Jericho fell. (Jos 2:1-24; 6:1, 22-25; Heb 11:31) Other instances of spying are mentioned at Judges 1:22-26; 18:1-10, 14, 17; 1 Samuel 26:4. David’s messengers to King Hanun of Ammon were charged with being spies and were mistreated. (2Sa 10:1-7) Absalom sent spies  throughout Israel, not so much to gain information for his conspiracy against David as to stir up support for his subversive cause.​—2Sa 15:10-12.

The apostle Paul wrote about his visit to Jerusalem with Barnabas and Titus, mentioning that at the time there were “false brothers brought in quietly, who sneaked in to spy upon our freedom which we have in union with Christ Jesus.”​—Ga 2:1-5.