Came across this nice Mishnah:

[There are] seven things [characteristic] in a clod, and seven in a wise man:

1) A wise man does not speak before one who is greater than he in wisdom,

2) And does not break into his fellow’s speech;

3) And is not hasty to answer;

4) He asks what is relevant, and he answers to the point;

5) And he speaks of the first [point] first, and of the last [point] last;

6) And concerning that which he has not heard, he says: I have not heard;

7) And he acknowledges the truth.

And the reverse of these [are characteristic] in a clod.