John Wesley on Genesis 8:8

He sent forth a dove - Which returned the first time with no good news, but probably wet and dirty; but the second time she brought an olive leaf in her bill, which appeared to be fresh plucked off; a plain indication that now the trees began to appear above water. Note here, that Noah set forth the dove the second time, seven days after the first time, and the third time was after seven days too: and probably the first sending of her out was seven days after the sending forth of the raven. The olive branch is an emblem of peace.