man of my word
A reliable person, who always keeps their promises or is known to fulfill their commitments and obligations at any cost. Someone you can sincerely trust to do something when asked.
Example:
"Don't worry, I'll never tell your wife about that, I'm a man of my word."
"I have no doubt that he'll pay you back, He's a man of his word."
"Don't worry, I'll never tell your wife about that, I'm a man of my word."
"I have no doubt that he'll pay you back, He's a man of his word."