'Voluntary' in the Bible

You shall be careful to perform that [vow] which passes your lips, just as you have made a voluntary vow to the Lord your God, just as you have promised with your own words (mouth).

“Your gates will be open continually;They shall not be shut day or night,So that people may bring to you the wealth of the nations—With their kings led in procession.

but I did not want to do anything without first getting your consent, so that your goodness would not be, in effect, by compulsion but of your own free will.