See now, that the word ‘Ki’ functions here in the sense of “perhaps”: Is the tree of the field perhaps a man that it should be included in the besieged town because of you, to suffer the tribulations of hunger and thirst like the people of the city? Why should you destroy it? (Translation by Artscroll)
כי האדם עץ השדה. הרי כי משמש בלשון דילמא שמא האדם עץ השדה להכנס בתוך המצור מפניך להתיסר ביסורי רעב וצמא כאנשי העיר למה תשחיתנו:
Rabbi Eliezer said: "I heard that a person who excessively tears his/her clothing in mourning receives a lashing [the punishment] for the prohibition against being wasteful (bal tashchit). How much more so [should one be liable for damaging] one's body." But maybe clothes are different, because [rending one's clothes] is damage that will not be undone?!...Whenever Rav Hisda passed through thorns and thistles he would lift up his garment, saying, [my body] can be healed, but [my clothes] can't be "healed."
אמר רבי אלעזר: שמעתי, שהמקרע על המת יותר מדאי - לוקה משום בל תשחית, וכ"ש גופו; ודלמא בגדים שאני, דפסידא דלא הדר הוא! כי הא דרבי יוחנן קרי למאני מכבדותא, ורב חסדא כד הוה מסגי ביני היזמי והגא, מדלי להו למאניה, אמר: זה מעלה ארוכה, וזה אינו מעלה ארוכה!
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. [translation by Dr. Akiva Wolff based on commentary of Rashi]
אמר רב זוטרא האי מאן דמיכסי שרגא דמשחא ומגלי נפטא קעבר משום בל תשחית
What difference is there between the death of young people and the death of old people?...R. Nehemiah says: When the fig is gathered in its due season it is good for the fig and for the tree; but when it is not gathered in its due season, it is bad for the fig and for the tree. Here is an illustration. R. Hiyya the elder and his disciples (other versions: R. Simeon b. Halafta and his disciples, R. Akiba and his disciples) were sitting and studying beneath a fig-tree. The owner of the tree arose early to gather its fruit.
ב מה בין מיתת נערים למיתת זקנים, ר' יהודה ור' נחמיה...