"He has sworn to what is bad for himself, and yet he does not alter it."
Watchtower 2006, May 15, page 19 - Subtitle 4, Lessons for us in Psalm 15:4
Watchtower 1995, May 1, Page 29 - Subtitle: "Stick to your Word"
Watchtower 1989, Sept. 15, Pages 28-29 - Subtitle: "He has sworn to what is bad for himself and yet he does not alter."
"The principle here is that of fulfilling our promises... Even if we later find that doing what we promised is very difficult, [or not something we want to do] we should not change our mind and renege on our promise [what we have agreed to do] ... If we swear to do something... we should live up to it. " (direct quote)