Ass in Fausset's Bible Dictionary

Hebrew athon; from athan, 'short in step". 1. The domestic she ass, named so from its slowness. 2. The chamor, the he ass, whether domesticated or not, distinguished from the athon; Genesis 45:23. From chamar, "red," as the Spaniards call the donkey "burro," from its red color. Used in riding and plowing. Not held in contempt for stupidity, as with us. Issachar is compared to an "ass, strong boned, crouching down between the hurdles (Genesis 49:14): he saw that rest was a good and the land pleasant; so he bowed his shoulder to bear, and became servant unto tribute;" ease at the cost of liberty would be his characteristic. Robust, and with a prime agricultural inheritance, his people would strive after material good, rather than political rule. The prohibition of horses rendered the donkey the more esteemed in Israel. In the E. it is a far superior animal to ours...

Link: https://bible-history.com/faussets/A/Ass/