The two extremes are given to refer to all of the sky, including the sun, moon, stars, and planets, and all of the earth. Alternate translation: "The sky, the earth, and everything in them" (See: [[rc://en/ta/man/jit/figs-merism]])
Jesus speaks of words not losing their power as if they were something that will never physically die. Alternate translation: "my words will never lose their power" (See: [[rc://en/ta/man/jit/figs-metaphor]])