"between a man": to exclude a minor — whence they ruled: Orphans (who are minors) are not subject to adjudication.
"between a man and his brother": This tells me only of the foregoing. Whence do I derive (the same for) one woman vis-à-vis another, one tribe, one family? From "Hear among your brothers" (All Jews are "brothers.") "and between his ger":
One who "piles up" ("oger") claims against him, saying "You plowed in my land" — and he denies it; "your ox killed my servant" — and he denies it.
Variantly: "and between his ger" — his neighbor (one who lives ["gar"] near him.) Variantly: his groomsman. Variantly: his tenant.