Deuteronomy 20:19 When you besiege a town for many days, waging-war against it, to seize it: you are not to bring-ruin on its trees, by swinging-away (with) an ax against them, for from them you eat, them you are not to cut-down- for are the trees of the field human beings, (able) to come against you in a siege?
(יט) לא תשחית את עצה לנדוח עליו גרזן לא תשחית את העץ כדי לנדוח עליו גרזן משחית בלבד שלא לצורך אלא להזיק לבני העיר:
(19) לא תשחית את עצה לנדוח עליו גרזן, do not destroy its trees merely in order to practice wielding an axe. Destruction must not be wanton; it is justified only if it serves to harm the enemy residing within the city.
(יט) כי האדם עץ השדה כי האמנם עץ השדה האדם ראוי לבא מפניך בגללו העיר במצור למסור את עצמם בידך מכח מצור וכיון שאינו כן בזה גם שראוי להזיק ליושבי העיר בכלי מלחמה כמו בסוללות וזולתם להביא העיר במצור. הנה בהיות שלא תשיג זה בהשחתת האילנות אין ראוי להשחיתם כמו שראוי שתשחית האדם יושבי העיר:
Is then the tree of the field a man? Is then the tree of the field a man who is capable of submitting to you that the city be besieged on its, account, and be forced to surrender because of the siege? This is (obviously) not so, and although it is acceptable to inflict damage upon the inhabitants of a city with implements of war and other kinds of (tactics) so as to besiege the city, since you will not attain (this goal) by destroying the trees, it is improper to destroy them. (Yet, it is still) proper that you destroy the people who dwell in the city.
א לְהַשְׁחִית אִילָנֵי מַאֲכָל שֶׁתִּדְבַּק בָּנוּ הַטּוֹבָה, וְנַרְחִיק מִכָּל דָּבָר רָע וּמִכָּל כָּ ...שּׁרֶֹשׁ הַמִּצְוָה יָדוּעַ , שֶׁהוּא כְּדֵי לְלַמֵּד נַפְשֵׁנוּ לֶאֱהבֹ הַטּוֹב וְהַתּוֹעֶלֶת וּלְהִדָּבֵק בּוֹ, וּמִתּוֹ יְאַבְּדוּ אֲפִלּוּ גַּרְגִּיר שֶׁל הַחֲסִידִים וְאַנְשֵׁי מַעֲשֶׂה אוֹהֲבִים שָׁלוֹם וּשְׂמֵחִים בְטוּב הַבְּרִיּוֹת וּמְקָרְבִים אוֹתָן לַתּוֹרָה, ְדְּבַר הַשְׁחָתָה, וְזֶהוּ דֶּרֶ חַרְדָּל בָּעוֹלָם, וְיֵצַר עֲלֵיהֶם בְּכָל אֲבַדּוֹן וְהַשְׁחָתָה שֶׁיִּרְאוּ, וְאִם יוּכְלוּ לְהַצִּיל יַצִּילוּ כָּל דָּבָר מֵהַשְׁחִית בְּכָל כּחָֹם...
“The root reason for the precept [of Bal Tashchit/do not destroy] is known: for it is in order to train our spirits to love what is good and beneficial and to cling to it; and as a result, good fortune will cling to us, and we will move well away from every evil thing and from every matter of destructiveness. [This is the way of the kindly men of piety and the conscientiously observant; they love peace and are happy at the good fortune of people, and bring them near the Torah.] They will not destroy even a mustard seed in the world, and they are distressed at every ruination and spoilage that they see; and if they are able to do any rescuing, they will save anything from destruction, with all their power.”
...אמר רב זוטרא האי מאן דמיכסי שרגא דמשחא ומגלי נפטא קעבר משום בל תשחית...
One who covers an oil lamp [causing the flame to burn inefficiently] or uncovers a kerosene lamp [allowing the fuel to evaporate faster] violates the prohibition of bal tashchit.
ולא האילנות בלבד, אלא כל המשבר כלים, וקורע בגדים, והורס בניין, וסותם מעיין, ומאבד מאכלות דרך השחתה--עובר ב”לא תשחית”
Mishneh Torah, Laws of Kings 6:10
Not only one who cuts down a fruit tree, but anyone who destroys household goods, tears clothing, demolishes a building stops up a spring, or ruins food deliberately, violates the prohibition of Bal Tashchit,‘do not destroy.'
Genesis 1:11 God said: Let the earth sprout forth with sprouting-growth, plants that seed forth seeds, fruit trees that yield fruit, after their kind, (and) in which is their seed, upon the earth! It was so. Genesis 1:12 The earth brought forth sprouting-growth, plants that seed forth seeds, after their kind, trees that yield fruit, in which is their seed, after their kind. God saw that it was good.
(י) אַרְבַּע מִדּוֹת בָּאָדָם. הָאוֹמֵר שֶׁלִּי שֶׁלִּי וְשֶׁלְּךָ שֶׁלָּךְ, זוֹ מִדָּה בֵינוֹנִית. וְיֵשׁ אוֹמְרִים, זוֹ מִדַּת סְדוֹם. שֶׁלִּי שֶׁלָּךְ וְשֶׁלְּךָ שֶׁלִּי, עַם הָאָרֶץ. שֶׁלִּי שֶׁלָּךְ וְשֶׁלְּךָ שֶׁלָּךְ, חָסִיד. שֶׁלִּי שֶׁלִּי וְשֶׁלְּךָ שֶׁלִּי, רָשָׁע:
There are four character types among people: One who says “My property is mine and yours is yours” is an average character type, but some say the characteristic of Sodom. One who says, “mine is yours and yours is mine” is an unlearned person. One who says, “Mine is yours and yours is yours” is pious. One who says “Yours is mine and mine is mine” is wicked.
אִם הָיְתָה נְטִיעָה בְּתוֹךְ יָדָךְ וְיֹאמְרוּ לָּךְ "הֲרֵי לָךְ הַמָּשִׁיחַ", בּוֹא וּנְטַע אֶת הַנְטִיעָה וְאַחַר כָּךְ צֵא וְהַקְבִּילוֹ
Avot d'Rabbi Natan 31b
Rabbi Yohanan ben Zakkai used to say: If you have a sapling in your hand and are planting it, and someone should say to you that the Messiah has come, stay and complete the planting, and only then go to greet the Messiah.