(טו) לֹא־תַעֲשׂ֥וּ עָ֙וֶל֙ בַּמִּשְׁפָּ֔ט לֹא־תִשָּׂ֣א פְנֵי־דָ֔ל וְלֹ֥א תֶהְדַּ֖ר פְּנֵ֣י גָד֑וֹל בְּצֶ֖דֶק תִּשְׁפֹּ֥ט עֲמִיתֶֽךָ׃ (טז) לֹא־תֵלֵ֤ךְ רָכִיל֙ בְּעַמֶּ֔יךָ לֹ֥א תַעֲמֹ֖ד עַל־דַּ֣ם רֵעֶ֑ךָ אֲנִ֖י יְהֹוָֽה׃ (יז) לֹֽא־תִשְׂנָ֥א אֶת־אָחִ֖יךָ בִּלְבָבֶ֑ךָ הוֹכֵ֤חַ תּוֹכִ֙יחַ֙ אֶת־עֲמִיתֶ֔ךָ וְלֹא־תִשָּׂ֥א עָלָ֖יו חֵֽטְא׃ (יח) לֹֽא־תִקֹּ֤ם וְלֹֽא־תִטֹּר֙ אֶת־בְּנֵ֣י עַמֶּ֔ךָ וְאָֽהַבְתָּ֥ לְרֵעֲךָ֖ כָּמ֑וֹךָ אֲנִ֖י יְהֹוָֽה׃
(15) You shall not render an unfair decision: do not favour the poor or show deference to the rich; judge your kin fairly. (16) Do not deal basely with members of your people. Do not profit by the blood of your fellow [Israelite]: I am the Eternal. (17) You shall not hate your kinsfolk in your heart. Reprove your kin but incur no guilt on their account. (18) You shall not take vengeance or bear a grudge against members of your people. Love your fellow as yourself: I am the Eternal.
(2) BUT THOU SHALT LOVE THY NEIGHBOR. Many are of the opinion that the lamed of le-re’akha (thy neighbor) is superfluous. It is like the lamed of le-avner (Abner) (II Sam. 3:30). I believe that le-re’akha is to be taken literally. Its meaning is that one should love that which is good for one’s neighbor as one does for oneself.
(17) For your God יהוה is God supreme and Ruler supreme, the great, the mighty, and the awesome God, who shows no favor and takes no bribe, (18) but upholds the cause of the fatherless and the widow, and loves the stranger, providing food and clothing.—
There was another incident involving one gentile who came before Shammai and said to Shammai: Convert me on condition that you teach me the entire Torah while I am standing on one foot. Shammai pushed him away with the builder’s cubit in his hand. The same gentile came before Hillel. He converted him and said to him: That which is hateful to you do not do to another; that is the entire Torah, and the rest is its interpretation. Go study.
Setting Ourselves up for Success - Parashat Aharei Mot-Kedoshim by Dena Weiss 2018
The verse appears to demand active, strong and true love, whereas Hillel transforms the commandment in two ways through his reformulation: “That which is hated by you, you may not do to your friend.” The first change that he makes is to move away from love to “not-hate.” You are no longer commanded to love your neighbor, it is sufficient to merely refrain from hating him. The second shift is that the area of love is no longer a place of emotion and feeling, but rather a place of action: feeling hateful is not the problem. What is problematic is acting in a hateful way.
Hillel is able to make these two shifts by employing a different understanding of the way that the two halves of the verse relate to each other. In the initial reading of the verse, which appears to mandate emotion, you must love your neighbor—thereforeyou may not take revenge on him or treat him with resentment. Loving your neighbor is the primary commandment from which the secondary prohibition not to take revenge flows. The way that Hillel reads this verse וְאָהַבְתָּ לְרֵעֲךָ כָּמוֹךָ is not a commandment that produces a prohibition. Rather וְאָהַבְתָּ לְרֵעֲךָ כָּמוֹךָ is a promise that you will inevitably love your neighbor as yourself as a consequence of treating him in a loving way. Don’t do back to him the hateful things that he has done to you. And if you can’t do hateful things to someone who, in some sense, deserves them, you obviously may not treat an innocent friend in a bad way. If you follow the guidance of not engaging in spiteful behavior, then you will automatically be loving your neighbor as yourself.
(א) היא שצונו לאהוב קצתנו את קצתנו כאשר נאהב עצמנו ושתהיה אהבתו וחמלתו לאחיו כאהבתו וחמלתו לעצמו בממונו ובגופו וכל מה שיהיה ברשותו אם ירצה אותו ארצה אני אותו וכל מה שארצה לעצמי ארצה לו כמוהו. והוא אמרו יתעלה ואהבת לרעך כמוך. (קדושים תהיו, מדע הלכות דעות פ"ז):
(1) That is that God commanded us to love each other like we love ourselves, and that one's love and compassion for one's fellow be like the love and compassion for oneself regarding their money - regarding their body and regarding everything that is in their domain. If they want it, I want it; and all that I will want for myself, I will want the same for them. And that is God saying, "and you shall love your neighboir as yourself" (Leviticus 19:18). (See Parashat Kedoshim; Mishneh Torah, Human Dispositions 7.)
Loving Our Neighbor: A Call to Emotion and Action by Rabbi Shai Held
Let's look more closely at our text. The unit in which our verse appears reads, in full: "You shall not hate your kinsfolk in your heart. Reprove your kinsman but incur no guilt because of him. You shall not take vengeance or bear a grudge against your countrymen. Love your neighbor as yourself: I am the Lord" (Leviticus 19:17-18). Love is contrasted here with hate (sin'ah ba-lev) - and since hatred is clearly an emotion, it would make sense that love, as it used here, would be too. Moreover, if not hating can be commanded, then surely loving can as well. It seems clear, then, that the Torah does make demands on what we feel. Bible scholar Tamar Kamionkowski is thus on the mark in maintaining that these verses do indeed "command what one ought to feel" and that they "deal with intentions and emotions."...
In general, the Torah does not drive a wedge between action and emotion; on the contrary, its ideal is to integrate them - to feel passionately about God and to observe God's commandments, to care about people and to act caringly towards them. The argument that the Torah obligates us to do but not to feel strikes me as alien to the Torah's vision of ethics, which asks me both to do and to feel. When the Torah asks for love, it is calling for doing and feeling, not doing rather than feeling.
Can God Prohibit an Emotion? by Prof. Sarah Wolf 2021
Yet the idea that we have control over our emotional states may not be as foreign to a contemporary mindset as it would initially seem. How many of us have tried to cultivate gratitude by keeping a journal or a list at the end of the day? Or attempted to boost our own confidence by assuming a “power pose”? Our society is perhaps again realizing something that the ancient Rabbis took for granted: the boundary between our inner selves and our outer selves is not as sharp as we may have once thought, and that there is significant permeability between the two. What we do with our bodies affects how we feel, and vice versa.
Emotion - The Stanford Encyclopaedia of Philosophy
A widely shared insight is that emotions have components, and that such components are jointly instantiated in prototypical episodes of emotions. Consider an episode of intense fear due to the sudden appearance of a grizzly bear on your path while hiking. At first blush, we can distinguish in the complex event that is fear an evaluative component (e.g., appraising the bear as dangerous), a physiological component (e.g., increased heart rate and blood pressure), a phenomenological component (e.g., an unpleasant feeling), an expressive component (e.g., upper eyelids raised, jaw dropped open, lips stretched horizontally), a behavioral component (e.g., a tendency to flee), and a mental component (e.g., focusing attention).

אָמַר רַבִּי אָבִין: מַאי קְרָאָה — ״לֹא יִהְיֶה בְךָ אֵל זָר וְלֹא תִשְׁתַּחֲוֶה לְאֵל נֵכָר״, אֵיזֶהוּ אֵל זָר שֶׁיֵּשׁ בְּגוּפוֹ שֶׁל אָדָם? הֱוֵי אוֹמֵר, זֶה יֵצֶר הָרָע.
Rabbi Avin said: ... “There shall not be a strange god within you, and you shall not bow to a foreign god” (Psalms 81:10). What is the strange god that is within a person’s body? Say that it is the evil inclination.
(א) בֶּן זוֹמָא אוֹמֵר...אֵיזֶהוּ גִבּוֹר, הַכּוֹבֵשׁ אֶת יִצְרוֹ...
(1) Ben Zoma said:...Who is mighty? One who subdues their own inclination...