Fine words butter no parsnips
Old English Proverb
The meaning is that words alone are useless, especially flattering phrases or fine promises, and you should judge people by what they do rather than by what they say. The origin of this proverb is unknown, but appears to be at least 400 years old.
By the way, to butter someone up means to flatter someone, often with an ulterior motive to persuade them to do something.
– These flowers are lovely. Are you trying to butter me up?