Deuterocanon

Sirach 13:15-24

15 Every creature loves its like,
and every person the neighbor.
16 All living beings associate with their own kind,
and people stick close to those like themselves.
17 What does a wolf have in common with a lamb?
No more has a sinner with the devout.
18 What peace is there between a hyena and a dog?
And what peace between the rich and the poor?
19 Wild asses in the wilderness are the prey of lions;
likewise the poor are feeding grounds for the rich.
20 Humility is an abomination to the proud;
likewise the poor are an abomination to the rich.
21 When the rich person totters, he is supported by friends,
but when the humble falls, he is pushed away even by friends.
22 If the rich person slips, many come to the rescue;
he speaks unseemly words, but they justify him.
If the humble person slips, they even criticize him;
he talks sense, but is not given a hearing.
23 The rich person speaks and all are silent;
they extol to the clouds what he says.
The poor person speaks and they say, “Who is this fellow?”
And should he stumble, they even push him down.
24 Riches are good if they are free from sin;
poverty is evil only in the opinion of the ungodly.

Rabbinic

Bava Kamma 92b

Rabba bar Mari explains each of the sources. It is written in the Torah, as it is written: “And so Esau went to Ishmael”. It is repeated in the Prophets, as it is written: “And there were gathered vain fellows to Yiftah, and they went out with him”. And it is triplicated in the Writings, as it is written: All fowl will live with its kind, and men with those like him. We learned it in a mishna: All that is attached to that which is ritually impure is ritually impure; all that is attached to that which is ritually pure is ritually pure. And we learned it in a baraita: Rabbi Eliezer says: Not for naught did the starling go to the raven but because it is its kind, as it too is a non-kosher bird.