The word "eyes" here represents the people of the nation of Israel. AT: "out in the open where all of the nation of Israel may see" (See: [[rc://en/ta/man/translate/figs-synecdoche]])
Samuel knows it is harvest time. He is using a rhetorical question to emphasize that it does not usually rain at this time so the people will know that the rain that will ruin their harvest is a judgment from Yahweh. AT: "It is harvest time and does not usually rain at this time" (See: [[rc://en/ta/man/translate/figs-rquestion]])