Isaiah 12:1
12:1 And in that day thou {a} shalt say, O LORD, I will praise
     thee: though thou wast angry with me, thy anger is turned
     away, and thou didst comfort me.

     (a) He shows how the Church will praise God, when they are
         delivered from their captivity.

Isaiah 12:2
12:2 Behold, God [is] my {b} salvation; I will trust, and not be
     afraid: for the LORD [is] my strength and [my] song; he
     also is become my salvation.

     (b) Our salvation stands only in God, who gives us an
         assured confidence, constancy and opportunity to praise
         him for the same.

Isaiah 12:3
12:3 Therefore with joy shall ye {c} draw water out of the wells
     of salvation.

     (c) The graces of God will be so abundant that you may
         receive them in as great plenty as waters out of a
         fountain that is full.

Isaiah 12:6
12:6 Cry aloud and shout, {d} thou inhabitant of Zion: for great
     [is] the Holy One of Israel in the midst of thee.

     (d) You who are of the Church.