take one at word
take (one) at (one's) word
To accept what one says without further verifying or investigating. Why some people take that pundit at his word is beyond me. He clearly has an ulterior motive. You're right to be wary, but, in this case, I think we can take John at his word. He's just trying to help.
take one at one's word
to believe what someone says and act accordingly. She told me to go jump in the lake, and I took her at her word. You shouldn't take her at her word. She frequently says things she doesn't really mean.