Psalms 119:108 Accept, I beseech thee, the freewill offerings of my mouth, O LORD, and teach me thy judgments.

The might of this verse has been understood since ancient times as this is the last verse recited before they blow the Shofar on Rosh Hashana Link to this reference. It would appear the Psalmist made a deal with God, "if I give this offering will you teach me." Like Hannah this type of vow is a soul thing and thus in the NUn section... Robby shares a story along these lines.

http://christiancarguy.com/

Psalms 119:108