Somebody’s word is their bond
Definition 1 of 1
Pro Tip 1/3Promise Keeper
Indicates someone's consistent commitment to honor their promises. 
I knew I could count on her—her word is her bond.
Pro Tip 2/3Trust Indicator
Shows a strong basis for trust in personal and professional relationships. 
In our business dealings, his word is his bond, and that's everything.
Pro Tip 3/3Character Strength
Reflects a person's integrity and strong moral principles. 
When voting, consider if the candidate's word is their bond.