Hi,
"When Rabbi Pinchas ben Yair came to Rebbe's home, he sought to enter through a passage where [he found that] a white mule stood. He exclaimed, 'The angel of death [for white mules were particularly vicious] is in this house; how could I eat with him?'
"Rebbe heard this and exited to greet him. He said, 'Should I sell it?!' To which Rabbi Pinchas ben Yair replied, 'You shall not put a stumbling block before the blind!'
"He said, 'I will abandon it!' To which Rabbi Pinchas ben Yair replied, 'You will increase the harm! '
"He said, 'I will remove its hooves!' To which Rabbi Pinchas ben Yair replied, 'This will pain a living creature!'
" He said, 'I will kill it!' To which Rabbi Pinchas ben Yair replied, 'That would violate the prohibition against waste!'
(Talmud, Chullin 7b)
Have a great day,
Mordechai