'Fences' in the Bible

Why hast thou broken down its fences, so that all who pass by the way do pluck it?

Words of the wise are as goads, and as fences planted by the masters of collections, they have been given by one shepherd.

Wail, O Heshbon, for Ai is laid waste; cry, ye daughters of Rabbah, gird you with sackcloth: lament, and run to and fro among the fences; for Malcam shall go into captivity, his priests and his princes together.

And the lord said to the bondman, Go out into the ways and fences and compel to come in, that my house may be filled;