Musar zu Jirmejahu 20:7

The second type is the one who mocks the words of people because he holds them in contempt because they too did not prosper in money matters and in the attainment of honor, and he makes fun of the poor. Not that he accuses them of any defect; they are simply despicable in his eyes. And this comes about because of arrogance or, at times, because the scoffer has ease and too much pleasure, as it is said, "Our soul is full sated with the scorning of those that are at ease, and with the contempt of the proud oppressors" (Ps. 123:4). This is proof that those who live at ease are often scoffers, and at times because of their great security they mock the righteous, as it is said, "Every one mocketh me" (Jer. 20:7). And it is said, "Whoso mocketh the poor blasphemeth his Maker" (Prov. 17:5). The explanation is that he who laughs at the poor man because he is poor, does so because it seems to him that the man is poor because of his lack of wisdom while he himself is rich because of his wisdom, as it is said, "My power and the might of my hand hath gotten me this wealth" (Deut. 8:17). Thus, he who scoffs at a poor man reviles the Creator. For he (the poor man) is the work of God, as it is written, "The rich and the poor meet together — The Lord is the maker of them all" (Prov. 22:2). And therefore he is really scoffing at the word of God, Blessed be He.