敵に塩を送る
(Teki ni shio wo okuru; “To send your enemy salt”)

Definition:

When an opponent is having some difficulty in distress, to offer aid instead of taking the opportunity to strike. May especially apply if the distress is unrelated to the area in which you’re confronting each other. Being a good sport, an honorable and merciful combatant, etc. Compare and contrast 切磋琢磨.

Breakdown:

We begin with the noun 敵 (teki), “enemy.” The directional particle に (ni) marks this noun as the recipient or destination of the verb 送る (okuru), “to send, “ in sentence-final (or prenominal) form, while the particle を (wo) tells us that the verb’s direct object is the noun 塩 (shio), “salt.”

Notes:

I think I was still in high school when I came across and read the “Perfect Collection” translation of Mai, The Psychic Girl (a relatively obscure manga about people with telekinetic powers). One of the things that struck me at the time, and left a lasting impression, was the fact that one of the early antagonists – a life-or-death foe – later became an ally of the protagonists. The idea of seeing enemies as potential friends seems a very positive and promising one, to me, especially in comparison to our current no-holds-barred, winner-takes all sociopolitical environment.

This saying is attributed to the Sengoku period, when Uesugi Kenshin (上杉謙信) supposedly heard that the Hōjō clan had cut off the salt supply of Kai province (which was ruled by his rival Takeda Shingen (武田信玄) and responded by… sending salt to Kai Province, commenting that he preferred swords over salt as a means of doing battle.

Be careful not to confuse this with “to rub salt in someone’s wounds” — that expression denotes marked cruelty or enmity, while this one indicates marked kindness and understanding.

Example sentence:

敵に塩を送ることは理想的な行為だが、闘気や敵意を抑え、実行することは非常に難しい。

(Teki ni shio wo okuru koto wa risouteki na koui da ga, touki ya tekii wo osae, jikkou suru koto wa hijou ni muzukashii.)

[Offering your hand to an opponent in need is the ideal, but it can be extremely challenging to suppress one’s combativeness or hostility and put that ideal into practice.]