In Mosiah 9:1 we learn that Zeniff had been "sent as a spy among the Lamanites." From a few key items in the verses that follow, the reader can deduce some facts about this spy mission.
(1) First, Zeniff had "a knowledge of the land of Nephi" (v. 1). It is likely that when Mosiah's group had originally fled the land of Nephi, they left behind many diverse linguistic and cultural "Nephites" who were now classified as "Lamanites" only because they fit the definition of all people who did not follow the ways of Nephi. Zeniff says that he "had been taught in all the language of the Nephites." (v. 1) Thus, Zeniff was apparently asked to be a spy because he was linguistically qualified to communicate with such a culturally diverse group.
(2) Second, Zeniff must have been young and strong. From verse 2 we find that Zeniff not only felt equal to the task of challenging an "austere and a bloodthirsty" commander in the wilderness, but survived the bloody battle which followed. Moreover, although the trip consisted of "many days" travel "up" through "wilderness" (vv. 4,3,2), Zeniff was "over-zealous" about going again. (v. 3)
(3) Third, because Zeniff had "a knowledge of the land of Nephi" (v. 1), he had apparently been part of Mosiah's original exodus. If he was still young and vigorous, then his attempt to return to the land of Nephi probably occurred relatively soon after the arrival of the Nephites in the land of Zarahemla.
(4) Fourth, after surviving the original spying mission and returning again to the land of Nephi with another group, Zeniff indicates that he "went again . . . into the city." (v. 5) This possibly implies that on his original spy mission, Zeniff had gone into the city where he was able to talk with some of the people and witness their lifestyle. Indeed he says that he "saw that which was good among them." (v. 1) This apparently led him to oppose their destruction (see v. 2).
[Alan C. Miner, Personal Notes]
Geographical [Theory Map]: Mosiah 9:1-2 (Omni 1:27) Zeniff Is Part of a Failed Bid to Return to Lehi-Nephi (Year 407)