Parshas Ki Teitzei has the distinction of having the most mitzvos of any parsha in the Torah, namely seventy-four. I'd like to focus on one which, at first glance, is not relevant to most individuals, but upon deeper reflection, is truly most pertinent. The Torah teaches (Devarim 22:10), "You shall not plow with an ox and a donkey together." Rashi, citing the Sifri, provides the background of the verse from the Oral Law, to include coupling of any two different species, one kosher and the other not, for any kind of work.
While the Torah does not provide a reason for this prohibition, the Sefer HaChinuch (550) gives two reasons. He first quotes his rebbe, the Rambam, who sees this prohibition stemming from the prohibition of mating one animal with another species (as found in Vayikra 19:19), and having these animals work together in close proximity could lead to their mating. Interestingly, the Ibn Ezra notes that working the ox and donkey together would be a violation of tzar baalei chaim, inflicting pain on an animal. The donkey, which is the weaker of the two, cannot pull the load as well as the stronger ox. In addition, the Daas Zekeinim m'Baalei Tosfos suggest that the Torah is concerned about the feelings and sensitivities of the donkey. Both animals will be given their appropriate portions of food. The ox however, being a kosher animal, chews his cud, when the donkey hears the additional activity happening in the ox's stomach, the donkey will believe that the ox has been given more food, and will be psychologically distressed.
The Sefer HaChinuch therefore maintains that included as a logical extension of this mitzvah is the prohibition of being insensitive to the feelings of the next individual. He offers the following example: if a welcoming committee is being organized, do not intentionally pair together two individuals of different nature, such as an extrovert and an introvert, as the latter is going to feel deficient and incapable in this endeavor. To the Chinuch, this mitzvah is not to be reckoned among those that Hashem gave such as the prohibition of blood (see Devarim 12:23 and Rashi there) to provide the Jew with many mitzvos that he fulfills daily to provide us with greater merit, but this mitzvah is most relevant to all people at all times.
It is exciting to note that sensitivity to others is built in to, or serves as the reason for, many mitzvos and practices. To begin with, we find in this parsha that the Torah legislates the laws of shikcha, meaning if one forgets a sheaf of grain or fruit of trees, they are to leave it in the field for the poor and not go back and retrieve them. This law accompanies that of leket, the gleanings that fall during the harvest, and peah, the edge of the field that must be left unharvested for the poor. The common denominator to these agricultural mitzvos is that the Torah is teaching that these parts of the field are not yours, rather they belong to the poor. However, rather than their knocking on your door and you handing them the grain, here they work for it themselves, and this affords them dignity and the wonderful feeling of satisfaction of enjoying the fruits of their labor. Tremendous sensitivity for the poor.
A second example is the law (Shemos 22:24) that when a Jew lends another money, he may not act towards him as a creditor. What does that mean? It is clear that the borrower owes, yet the Torah is saying not to act aggressively to get your money. The Talmud (Bava Metzia 75b) understands this verse to mean that if Shabbos is a nice day, and the lender would like to take a walk, he can do so on any street in the neighborhood except that of the borrower. The reason for this is, lest the borrower think that the reason the lender is passing by his house is to remind him of the loan and his obligation, and he, the lender, would thus violate not to act towards him as an oppressor!
A third example of sensitivity is found in the laws of the repetition of the Shemoneh Esrei (Shulchan Aruch Orach Chaim 124). We are taught that Anshei Knesses HaGedolah enacted that after the congregation completes their private recitation of the amidah the chazzan is to repeat the entire prayer. The reason for this, as explained at the end of the Gemara Rosh Hashana, is to recite the prayer on behalf of the unlearned individuals who don't know how to formulate the amidah, who would thus fulfill their obligation by listening to the prayer of the chazzan. I'd like to ask a basic question: why do we repeat the Shemoneh Esrei at all times? Why not look around the shul or make an announcement, if anyone is in need of the repetition, please raise your hand? We don't do this, rather we always recite nineteen blessings without asking, lest somebody be embarrassed and publicly humiliated by having to request the repetition. We demonstrate sensitivity by reciting the repetition of the Shemonah Esrei.
A fourth example is from Tanach. We are taught in the first chapter in the first book of Shmuel (the Haftorah for the first day of Rosh Hashana), that Penina (Chana's co-wife), angered her repeatedly, Rabbi Levi in the Gemara Baba Basra (16a) teaches that Penina's motives were pure and sincere. Chana had no children, and Penina who had many, would constantly speak of her children in Chana's presence which was extremely insensitive. Despite the purity of her motives, which was to encourage Chana to pray for children, we are taught that Penina was punished for her insensitivity. This is a most pertinent lesson of how careful we are to speak of our families in front of others who might not be as equally blessed. As mentioned above the essence of this mitzvah is applicable at all times or circumstances, especially in school settings where there are stronger or weaker students.
One final example is that of the mitzvah of tzedakah. The Rambam (Hilchos Matenos Aniyim 10:7) lists eight levels of fulfilling this mitzvah. The highest one is that of "v'hechezakta bo" (Vayikra 25:35), literally to take hold of the needy individual and give him a job, independence and dignity; to remove him from the category of being a taker to the potential of becoming a giver. Note, however, that each level above the next is affording greater sensitivity to the needy recipient. It is not only the giving but how the giving is done. If it is accompanied by words of encouragement and endearment, the same act of charity is significantly upgraded (Bava Basra 9b).
I'd like to note how very relevant this mitzvah is, especially now as we rapidly approach Rosh Hashana. The Talmud (Rosh Hashana 16a) teaches that our reciting verses of Malchios - Kingship on Rosh Hashana is in order to accept His sovereignty upon ourselves. The Sifri in Parshas Vezos HaBracha comments on the verse (33:5) "vayehi b'Yeshurun melech" that when we are united as a people, the more glorified and established as King Hashem is. The extent of His Kingship is commensurate with the unification of His subjects in their acceptance and allegiance to Him. Thus the prerequisite for coronating Hashem on Rosh Hashana, one of the primary reasons for blowing the shofar, is to assure Him that we are all united as a people. Thus it behooves us to implement "v'ahavta lreacha kamocha" (Vayikra 19:18), and not to plow with the ox and donkey, meaning, to show greater sensitivity to one another thereby assuring for us a warmer reception from our Father, our King.