Then it got a little problematic. Johanan, et al added a little plea to their prayer....please, God, we'll do anything You ask, if only You'll give us an answer.
But the Word that returned through Jeremiah was a hard one to hear. God did tell them what to do, but they were prone to disobedience.
"O remnant of Judah, the LORD has told you, 'Do not go to Egypt.' Be sure of this: I warn you today that you made a fatal mistake when you sent me to the LORD your God and said, 'Pray to the LORD our God for us; tell us everything he says and we will do it.' I have told you today, but you still have not obeyed the LORD your God in all he sent me to tell you. So now, be sure of this: You will die by the sword, famine and plague in the place where you want to go to settle. (Jeremiah 42: 19-22)Now, what exactly was that "fatal mistake"? Was it insincerity in prayer? Were they too late for God's mercy since they were already disobedient in their hearts? Were they too hasty about wanting answers?
I think a part of it is that God does not want us to swear. He wants us to surrender to Him, yet we owe Him more than words.
Above all, my brothers, do not swear—not by heaven or by earth or by anything else. Let your "Yes" be yes, and your "No," no, or you will be condemned. -James 5:12
And do not swear by your head, for you cannot make even one hair white or black. -Matthew 5:36
What would have made a better prayer? Perhaps it's better to pray that we desire to obey Him, rather than promising we will do it.
At any rate, God knew the motives of Johanen's heart, and what he was really asking. He knows our hearts as well, and will answer accordingly.