Here "he" refers to God's servant whom Isaiah compares to a very young tree. This emphasizes that he will appear weak. (See: [[rc://en/ta/man/jit/figs-simile]])
"parched earth" is hard and dry ground that will not allow plants to grow and represents where the servant of Yahweh will come. Alternate translation: "out of an impossible situation" (See: [[rc://en/ta/man/jit/figs-metaphor]])