Mat 21:2 Go into the village across from you, and right away you will find an tethered ass and a colt with her: untie [them], and bring [them] to me.
Mat 21:3 And if any [man] say anything to you, you should say, The Lord has need of them; and right away, he will send them.

There are two lessons here: 1. What you need is always at hand. You just have to look for it. 2. People will give you what you need if you ask from a perspective of having a shared belief.

"Ass" is from onos, which the common beast of burden. Like the English term, it carries a certain sense of derision in Greek.