And I will mislead them, and I will arouse in them [sinful] desires, and I will command them so they will slit the ears of cattle, and I will command them so they will change the creation of Allah." And whoever takes Satan as an ally instead of Allah has certainly sustained a clear loss. -- Qur'an 4:119
This makes me wonder why slitting the ears of cattle has any importance. It's certainly not something I could envisage being tempted to do, no matter how persuasive Satan is.
Question: What is the significance of slitting the ears of cattle in Qur'an 4:119?
Tafsir write:
...surely I will command them and they will cut up the cattle’s ears and this was done to the she-camels they called bahā’ir. -- Tafsir al-Jalalayn
...and surely I will command them and they will cut the cattle's ears, what is known as the Bahirah. -- Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
So perhaps this is an historical thing. (It doesn't seem related to Bahira.)