Jamieson, Fausset and Brown on 2 Corinthians 11:26

26. In--rather, "By": connected with 2Co 11:23, but now not with "in," as there, and as in 2Co 11:27, where again he passes to the idea of surrounding circumstances or environments [Alford, Ellicott and others].

waters--rather, as Greek, "rivers," namely, perils by the flooding of rivers, as on the road often traversed by Paul between Jerusalem and Antioch, crossed as it is by the torrents rushing down from Lebanon. So the traveller Sport lost his life.

robbers--perhaps in his journey from Perga to Antioch in Pisidia. Pisidia was notorious for robbers; as indeed were all the mountains that divided the high land of Asia from the sea.

the heathen--Gentiles.

in the city--Damascus, Ac 9:24, 25; Jerusalem, Ac 9:29; Ephesus, Ac 19:23.

false brethren--(Ga 2:4).