Allah, exalted be He, says, “...while it is hateful to you.” That is, fighting is hateful to you. Yet He also says, “It may well be that you dislike a thing while it is good for you, and it may well be that you love a thing while it is bad for you.”
The beginning of the verse deals specifically with fighting, whereas the closing clause is unrestricted: “you dislike a thing.” He did not say, “you dislike fighting,” but rather “a thing”—anything at all. A person may loathe something that happens and later discover that it was in fact good for him, or long for something to occur and then find that it brings harm. How many times has something you detested taken place, only for you to realize in the end that it contained your benefit—just as the Almighty said: “It may well be that you dislike a thing while it is good for you, and it may well be that you love a thing while it is bad for you.”
A similar statement appears in Surah al-Nisa’: “But if you dislike them, it may be that you dislike a thing and Allah places much good in it.” Here again He says “a thing,” not “them,” and “places much good in it,” not “in them.”
This principle is universal: by His decree, predestination, and wisdom, Allah may cause something you detest to occur, yet in the end it proves beneficial; and conversely, He may bring about something you imagine to be good, but its outcome is harmful. For this reason a person should constantly ask Allah for a good conclusion to all affairs.
The verse then says, “Allah knows, and you do not know.” Indeed, Allah knows while we do not, for His knowledge is boundless—He knows the unseen future and everything else—whereas our knowledge is limited and deficient.