Jamieson, Fausset and Brown on Numbers 11:25

25. when the spirit rested upon them, they prophesied, and did not cease--As those elders were constituted civil governors, their "prophesying" must be understood as meaning the performance of their civil and sacred duties by the help of those extraordinary endowments they had received; and by their not "ceasing" we understand, either that they continued to exercise their gifts uninterruptedly the first day (see 1Sa 19:24), or that these were permanent gifts, which qualified them in an eminent degree for discharging the duty of public magistrates.