5. Every valley, &c.—levelling and smoothing, obvious figures, the sense of which is in the first words of the proclamation, "Prepare ye the way of the Lord."

     6. all flesh, &c.—(quoted literally from the Septuagint of Isa 40:5). The idea is that every obstruction shall be so removed as to reveal to the whole world the Salvation of God in Him whose name is the "Saviour" (compare Ps 98:3; Isa 11:10; 49:6; 52:10; Lu 2:31, 32; Ac 13:47).