You (really) said a mouthful.
Inf. Fig. You said exactly what needed to be said.; What you said was very meaningful and had great impact. Bill: Did you hear what I said to her? Jane: Yes. You said a mouthful. Was she mad? Bill: This is the worst food I have ever eaten. It is either stale, wilted, dry, or soggy! Tom: You said a mouthful!
you said a mouthful
What you said is absolutely true or important or relevant. This American colloquialism dates from the early 1900s. Dorothy Parker used it in Life (Feb. 3, 1921), “‘You said a mouthful.’ I confess.”