Jonah 2:8 & 9
"'Those who cling to worthless idols forfeit the grace that could be theirs. But I, with a song of thanksgiving, will sacrifice to you. What I have vowed I will make good. Salvation comes from the Lord.'" NIV translation
Grace (God giving us what we do not deserve) is evident throughout Jonah chapter two. God gave Jonah a second chance and, as we see in this passage, Jonah had settled in his heart that he would listen to God. He must have made a vow as he was dying something like: If you let me live, I will go to Nineveh as you have said. Jonah did not deserve any second chance but God granted it to him and he promised to listen and do what God had told him. When we come to Christ for salvation, we also vow to turn control of our lives over to Him (make Him Lord as well). Like Jonah, when we make a vow to God we should not do so lightly but we should count the cost and be prepared to keep the promise.