Here "these things" refer to the blessings and curses described in chapters 28-29. The phrase "have come on you" is an idiom that means to happen. Alternate translation: "When all these things happen to you" (See: [[rc://en/ta/man/translate/figs-idiom]])
This speaks of the blessings and curses that Moses told the people as if they were objects that he set in front of them. Alternate translation: "that I have just now told you about" (See: [[rc://en/ta/man/translate/figs-metaphor]])