Don't know if this helps, or not:

"The Septuagint, and some other ancient versions, make the latter part of the 116th Psalm" (commencing with the Psalm 116:10 -- I believed, therefore have I spoken) "a distinct Psalm, separate from the former, and some have called it the Martyr's Psalm, I suppose for the sake of Psalm 116:15." -- Henry's Commentary. -- Ed.

I'll have to go look up the reference.......don't know much of the Bible by heart.