3:7 planteth. Although men are privileged to sow the gospel seed, it still remains the work of God, for “the seed is the word of God” (Luke 8:11). Similarly, men may water the ground, but the water also is the word of God, “For as the rain cometh down, and the snow from heaven,…So shall my word be that goeth out of my mouth: it shall not return unto me void” (Isaiah 55:10-11).

3:8 are one. When God gives the increase, then “both he that soweth and he that reapeth [will] rejoice together” (John 4:36).