"to the stranger, to the orphan, and to the widow shall it be": It is written here "stranger," "orphan," and elsewhere (Ibid. 19) "stranger," "orphan." Just as there (it is shikchah) only when it contains less than two sa'ah, so, here.
(Devarim 25:1) "If there be a quarrel among men": Peace cannot result from a quarrel. And thus is it written (Bereshith 13:17) "And there was a quarrel between the herdsmen of Abraham's cattle and those of Lot's cattle." What is it that caused Lot to separate from that tzaddik (Abraham)? A quarrel. Here, too, what is it that caused this one to receive stripes (in beth-din)? [see verse 2]) A quarrel.