Why did I call it Sabra? Saying something in the name of I don’t say it.

Hello Rabbi,
I remember from the rabbi’s lessons that he mentioned two things and I would like to know where they are mentioned in the books (even if not an exact place, just to know where to look / by what sign).
I remember that the rabbi brought up that Beit Yosef writes that it is good to press the tongue for understanding.
And I also remember that the Rabbi quoted from one of the poskim that it is permissible to lie and say something in the name of the one who said it that he did not say. Because the words are examined in terms of the substance of the words. Not ad hominem.
I don’t want to bother the rabbi with looking. If he remembers, I’d be happy for him to write. Or at least my memory supports it.