Jack said he would call and he was as good as his word.
idiombe as good as your wordpromise to do exactly what you have promised to do:Stamford had promised to give Burdon all the help he could, and he was as good as his word.Becky turned out to be as good as her word, keeping the accounts in perfect order.
be as good as (one's) word
To be reliable and truthful. Said of one who typically follows through on one's promises. Tom is as good as his word—if he promised to help you move, then he'll be here.
be as good as your word
do what you have promised to do.
be as ˌgood as your ˈword
do what you have promised to do: You’ll find that she’s as good as her word — she always comes if she says she will.