To understand this important instruction it is necessary to recall how ancient Israelite land and property was delineated.
Each family/clan had an allocated piece of land to work and from which to collect harvests. Only rarely were fences used, instead, "boundary stones" were used to mark corners and edges of property.
If an unscrupulous adjacent farmer wanted to increase his harvest, he might be tempted to harvest some of the crop of his neighbor by either moving the boundary stone, or, simply collecting the harvest within the paddock for the first few paces. This was illegal as this text makes clear.
Ancient farmers for vigilant to this illegal behavior. However, if a family had no father, there was no one to police the boundary to ensure that part of the harvest was not stolen.
Prov 23:10, 11 contains two parts:
- A reminder that harvesting "over the boundary" was illegal
- In the case of the orphan or fatherless, it was God who might exact vengeance on such criminal activity
The Pulpit commentary arrives at the same conclusion:
Verses 10, 11. - An enlargement of Proverbs 22:28 combined with
Proverbs 22:22, 28. Verse 10. - Enter not into the fields of the
fatherless. Do not think to appropriate the fields of orphans, as if
there were no our to defend their rights (comp. Proverbs 15:25).
Benson add another dimension as well:
Proverbs 23:10-11. Enter not into the fields of the fatherless —
Either to take away their goods, or rather, to possess their lands, as
this phrase is used, 2 Samuel 5:6. For their Redeemer is mighty —
Hebrew, גאלם, their near kinsman, to whom it belongs to avenge their
wrongs, and to recover and maintain their rights: see on Leviticus
25:25; Numbers 35:12; Job 19:25. God is pleased to call himself the
kinsman of the fatherless, to show how much he concerns himself for
the relief of oppressed and helpless persons.