There is a person who sings the song of the Self. He finds everything, his complete spiritual satisfaction, within himself.
And there is a person who sings the song of the Nation. He steps forward from his private self, which he finds narrow and insufficiently developed. He yearns for the heights. He clings with a sensitive love to the entirety of the Jewish nation and sings with it its song. He shares in its pains, is joyful in its hopes, speaks with exalted and pure thoughts regarding its past and its future, investigates its inner spiritual nature with love and a wise heart.
There is a person whose soul is so broad that it expands beyond the border of Israel. It sings the song of humanity. This soul constantly grows broader with the exalted totality of humanity and its glorious image. He yearns for humanity’s general enlightenment. He looks forward to its supernal perfection. From this source of life, he draws all of his thoughts and insights, his ideals and visions.
And there is a person who rises even higher until he unites with all existence, with all creatures, and with all worlds. And with all of them, he sings. This is the person who, engaged in the Chapter of Song every day, is assured that he is a child of the World-to-Come.
And there is a person who rises with all these songs together in one ensemble so that they all give forth their voices, they all sing their songs sweetly, each supplies its fellow with fullness and life: the voice of happiness and joy, the voice of rejoicing and tunefulness, the voice of merriment and the voice of holiness.
The song of the soul, the song of the nation, the song of humanity, the song of the world-they all mix together with this person at every moment and at all times.
—Rabbi Abraham Isaac Hacohen Kook (1865-1935); OK 2, pp.444-445
(א) לְדָוִ֗ד מִ֫זְמ֥וֹר
לַֽ֭ה' הָאָ֣רֶץ וּמְלוֹאָ֑הּ
תֵּ֝בֵ֗ל וְיֹ֣שְׁבֵי בָֽהּ׃
(1) Of David. A psalm.
The earth is the LORD’s and the fullness thereof, the world and its inhabitants.
(9) The Holy One is good to all, and God's mercy is upon all creations.
And all your children shall be God's students, And great shall be the peace of your children;
You shall be established through righteousness. Stay far from cruelty and shall have no fear; From ruin, and it shall not come near you.
The Gemara cites an additional proof from a baraita: Come and hear: Great is human dignity, as it overrides a prohibition in the Torah.
The fundamental dignity of all creation is very precious to God. There is no value more precious than it.
--Rabbi Menachem ben Solomon haMeiri, commentary on the Talmud, Berachot 19b
In order to prepare humanity for the ethical goals of the end of days, mitzvot involved with eating meat were instructed in a specific way. As the prophet Isaiah says, "Stay far from cruelty and shall have no fear: (54:13-14). "You will have nothing to fear" because of the great distance from cruelty. This is not only talking about cruelty toward man, but toward all living creatures.
-- Rav Kook