“Strong enough to take a life
Are you strong enough to take care of one?”
“When a person takes life, then with the taking of life as a requisite condition, he produces fear & animosity in the here & now, produces fear & animosity in future lives, experiences mental concomitants of pain & despair; but when he refrains from taking life, he neither produces fear & animosity in the here & now nor does he produce fear & animosity in future lives, nor does he experience mental concomitants of pain & despair: for one who refrains from taking life, that fear & animosity is thus stilled.
-Buddha, Vera Sutta: Animosity
He goes on to repeat these same words in the context of each of the other four precepts, as well.