ולא תחנם, "and you are not to show them any favor.⁠" The word תחנם has been explained in many different ways. It may mean חן, grace, charm; it may mean חנינה, compassion, pardon. Clearly, the plain meaning is from חנינה, compassion, reprieve, and tells us that we must not indulge our feelings of compassion vis-a-vis these people. It is as if the Torah had written לא תחון אותם, "do not be charmed by them". According to the Talmud in Avodah Zarah 20 it is forbidden to even comment on the aesthetic beauty of artifacts designed in honor of idols. One must not even admire the physical features of a handsome Gentile or a beautiful Gentile woman. The Talmud suggests that this is part of the word לא תחנם when we read the letter ח as if it had the vowel chirik underneath it. They also understand the expression as meaning that we must not grant these people חניה "parking,⁠" i.e. temporary residence status and that it is forbidden to sell any land to Gentiles in the land of Israel. The Torah spelled out the reason when it said "so that they will not lead you into sin.⁠" You must also not give them any gift, including land, the letters in the word תחנם being read with the vowel pattern patach, sheva, patach, i.e. tachnam. In fact, the word lends itself to still further permutations by changing the vowel pattern. Basically, the sages demonstrate the power of the written Torah, which, because it does not have vowels or other signs such as commas and period signs, is capable of being interpreted in so many different ways. Changing the vowel pattern can give a single word many different meanings. Having appreciated this you will understand even better the power inherent in the names of God which lend themselves to so many permutations, i.e. different emphasis of the basic concept of Hashem. I have elaborated on this already in my comments on Numbers 11,15.