The early sages (Tanaaim) ordered that Scriptural words which are blatant and derogatory should be replaced with words that are “cleaner.” Thus, for example, the word ba’apolim, which in their era was a coarse word, is replaced with the word ba’yechorim when the verse “The Lord will strike you with the boils of Egypt, with hemorrhoids [apolim/techorim, with the scab, and with the itch, from which you cannot be healed” (Deuteronomy 28:27). This is one of the reasons why some Scriptural words are written one way but read another way, a phenomenon known as kri v’ktiv. Similarly, the word yishgalenah is replaced by yishkavenah in the verse “You shall betroth a wife, but another man shall lie with her [yishgalenah/yishkavenah]; you shall build a house, but you shall not dwell in it; you shall plant a vineyard, but shall not gather its grapes” (Deuteronomy 28:30).Similarly, the word chiryonim [dove excrement] is replaced by divyonim [dove secretions] in the verse “one-fourth of a kab of dove droppings [chiryonim/divyonim] for five shekels of silver” (II Kings 6:25). Also, the word choreihem is replaced by tzo’asam and shineihem is replaced by meimei ragleihem in the verse “[Has he] not [sent me] to the men which sit on the wall, that they may eat their own dung [choreihem/tzo’asam], and drink their own piss [shineihem/meimei ragleihem] with you?” (II Kings 18:27, see also Isaiah 36:12). Also, the word l’machara’ot is replaced by l’motza’ot in the verse “Then they broke down the sacred pillar of Baal and tore down the temple of Baal and made it a refuse dump [l’machara’ot.l’motza’ot] to this day” (II Kings 10:27). The sage Rabbi Joshua son of Karcha championed reading the word l’machara’ot as written instead of using a euphemism, for the subject of the verse is a pillar sacred to idolatry. It is appropriate, he said, to belittle idolatry through coarse language. The scholar Rav Nachman added that all levity is forbidden except jokes at the expense of idolatry. The scholar Rav Acha son of Rav Ika said that a Jew may tell an idolater “Take your idol and stick it up your shin tav [buttocks].” The scholar said that one may belittle a person of whom it is widely said that he is an adulterer and call him a “stinking bastard.”
(Babylonian Talmud, Tractate Megillah 25b)