word is bond
Saying this means that what you are saying is absolutely correct, and you do not have to put up money to prove it, you just say it. The term originates from the financial markets where, historically, traders would tell each other, "my word is bond", i.e. my word is good enough, you don't need it in writing.
This term is also in the lessons of the Nation Of Islam and 5% "Have you not learned that your word is bond? Yes, my word is bond and bond is life, I shall give my life, before my word shall fail."
Cause I'm frontin' in my ride, and my word is bond -- L.L. Cool J (The Boomin' System ).