We have fraternal twin sons who are very different. They look like brothers, but not twins, and they have very different interests and personalities. When they were young (about five or six years old), Joshua was rather quiet and direct in his answers. When I would ask him questions his responses were usually short and to the point. After church every Sunday, I would ask him what he learned in Sunday school and he would say something like, "We learned about God," or "The story David and Goliath." There was no additional commentary on his part.
Jason, on the other hand, was a little chatterbox. When I would ask him what he learned, I would get a five to ten minute dissertation on the subject of that morning's lesson. There were times when Jason would be chattering away in a room not realizing everyone else had left to go elsewhere.
Jason reminds me of the prophet in our Lectionary text from the Old Testament. "For Zion’s sake I will not keep silent." The prophet will be a chatterbox for the Lord.
Perseverance is indispensable for faithfulness. The journey of faith is long and can be difficult. In Isaiah 62:1-5 the prophet declares his perseverance in declaring the word of the Lord until God fulfills God's promise to restore his people bringing them to Jerusalem from every direction no matter how far the distance. God's people in exile can hope because God has made a promise and the promise will be kept. Thus, it is possible for the prophet and the people "to keep on keeping on" because God will do the same.
God will not give up on Israel. Israel should not give up on God. The prophet provides the example by his unfailing proclamation.