Sirach 21:11-24

11 Whoever keeps the law controls his thoughts,
and the fulfillment of the fear of the Lord is wisdom.
12 The one who is not clever cannot be taught,
but there is a cleverness that increases bitterness.
13 The knowledge of the wise will increase like a flood,
and their counsel like a life-giving spring.
14 The mind of a fool is like a broken jar;
it can hold no knowledge.
15 When an intelligent person hears a wise saying,
he praises it and adds to it;
when a fool hears it, he laughs at it
and throws it behind his back.
16 A fool’s chatter is like a burden on a journey,
but delight is found in the speech of the intelligent.
17 The utterance of a sensible person is sought in the assembly,
and they ponder his words in their minds.
18 Like a house in ruins is wisdom to a fool,
and to the ignorant, knowledge is talk that has no meaning.
19 To a senseless person education is fetters on his feet,
and like manacles on his right hand.
20 A fool raises his voice when he laughs,
but the wise smile quietly.
21 To the sensible person education is like a golden ornament,
and like a bracelet on the right arm.
22 The foot of a fool rushes into a house,
but an experienced person waits respectfully outside.
23 A boor peers into the house from the door,
but a cultivated person remains outside.
24 It is ill-mannered for a person to listen at a door;
the discreet would be grieved by the disgrace.


Niddah 16b

The Gemara asks: And Rabbi Yoḥanan, how does he interpret that verse cited by Reish Lakish? The Gemara answers that Rabbi Yoḥanan requires that verse: “But he who despises his ways shall die,” to teach that which is written in the book of ben Sira: Three people I have hated, and a fourth I have not loved: A minister who frequents [hanirgal] drinking houses, as he disgraces himself and leads himself to ruin and death; and some say a different version of the text: A minister who chats [hanirgan] in drinking houses; and some say a third version: A minister who is short-tempered [hanirgaz] when in drinking houses.

That is the first that he hated. And the others are one who dwells at the highest point of the city, where everyone sees him; and one who holds his penis and urinates. And the fourth, whom he has not loved, is one who enters the house of another suddenly, without warning. Rabbi Yoḥanan says: And this includes even one who comes into his own house without prior warning, as the members of his household might be engaged in private activities.