This second occurrence of the command to “struggle” applies to “the prophet” in particular. The sense of struggle that the Quran intends by this imperative may be partly determined by context. See the analysis of these commands at 66.9. On “be stern with them,” see 9.123, 48.29, and 66.9.

Direct addresses to “the prophet” are not frequent in the Quran, and most of the occurrences come in Sūras 8, 33, and 66. Known as the “vocative,” this direct address instructs the prophet in how to deal with non-Muslims. See an analysis of the contexts of “Prophet!” at 66.1.