The angel of God said to him: ‘Why did you strike your donkey these three times? Behold I went out to impede you, for you had hastened on a road to oppose me. (Numbers 22:32)
Maimonides (d. 1204) cites the act of Bilaam striking his donkey as an example of tzaar baalei chaim – causing unnecessary pain and distress to an animal, which is prohibited by the Torah (Guide to the Perplexed III:7). Yet what is perplexing is that Bilaam was a non-Jewish prophet. While he may have had the ability to communicate with God, he was surely not bound by Torah law.
The Torah does not only forbid causing unnecessary suffering to animals, but it demands that we act positively to promote their wellbeing. For example, it is forbidden to couple different species of animals together to prevent the distress which could be caused to the weaker animal (Deuteronomy 22:10).
The Talmud, based on a verse in Deuteronomy (11:15) records the law that it is forbidden for a person to eat before he has fed his animal (Brachot 40a).
Maimonides explains that we are commanded to send away the mother bird before removing the young from the nest (Deuteronomy 22:7) because living creatures instinctively care for their young and suffer just like humans when they see their young taken away or slaughtered (Guide to the Perplexed III:48).
Rabbi Avraham HaCohen Kook (d. 1935) indicates that the laws which prohibit cruelty to animals and promote their well-being are designed to not only minimise animal suffering but are necessary to guard us against becoming desensitised. The safeguards which protect animals also encourage us to develop our sense of compassion towards every living creature (Chazon HaTzimchonut V’HaShalom Chapter 14).
This is why Bilaam was culpable; laws pertaining to animal cruelty are axiomatic and form part of a universal morality of which Bilaam should have known instinctively. The fact he cared more about his mission than the pain he might cause to his donkey revealed his true nature as a callous, self centred and cold-hearted individual (Horeb 17).