'Smooth' in the Bible

sends couriers by sea,in reed vessels on the waters.Go, swift messengers,to a nation tall and smooth-skinned,to a people feared far and near,a powerful nation with a strange language,whose land is divided by rivers.

At that time a gift will be brought to Yahweh of Hosts from a people tall and smooth-skinned, a people feared far and near, a powerful nation with a strange language, whose land is divided by rivers—to Mount Zion, the place of the name of Yahweh of Hosts.

Every valley will be lifted up,and every mountain and hill will be leveled;the uneven ground will become smoothand the rough places, a plain.

Your portion is among the smooth stones of the wadi;indeed, they are your lot.You have even poured out a drink offering to them;you have offered a grain offering;should I be satisfied with these?