Musar su Deuteronomio 23:8

We can better understand the reason that the Torah permits Edomites and Egyptians (of the third generation after conversion) to become fully fledged members of the Jewish people if we take a look at the historical development of Abraham, the first convert to Judaism. Both the second generation after Abraham, i.e. Isaac-Ishmael, and the third generation, i.e. Jacob-Esau, still contained a considerable amount of פסולת, spiritual refuse. Only the fourth generation of Abraham's descendants, Jacob's sons, were completely pure and had divested themselves of their spiritual waste. Esau actually became the means that Jacob received the blessing. As a recognition of this the third generation of converts descended from Esau/Edom are admitted as full fledged members. The Torah acknowledges this in 23,8: "Do not despise Edom for he is your brother;" this means that after living as a Jew for the third generation Esau once more qualifies as a brother of Jacob not only biologically but also spiritually. The same law applies to the absorption of Egyptians into the community of the Jewish nation. Our exile in Egypt actually commenced at the time G–d foretold Abraham about it at the covenant of the pieces in Genesis 15,13. Abraham was told that the fourth generation of his descendants would return to the land of Canaan. While in Egypt, the souls of the Jewish people were refined to the extent that they were able to become a nation comprising over 600,000 men of military age, a people that qualified for the title "Israel," the honorific title bestowed by G–d on Jacob. It is appropriate therefore that the third generation of an Egyptian convert to Judaism should enjoy full equality with other Jews just as Jacob who was the third generation counting from Abraham's conversion, was pure and had shed all the spiritual פסולת which had remained from the pollutant of the serpent. Israel, too, had remained גרים, strangers, in Egypt for three generations. The prohibition of bringing the wages of harlotry to the altar of G–d is explained simply by the fact that the harlot is beholden to Lilith, the antithesis of the שכינה. It is a domain where the dogs cry out because the angel of death is constantly around. This is why David prayed in his Psalm 22,21: "Save my life from the sword, my precious life from the clutches of a dog."