“I would rather save the life of one citizen than kill a thousand enemies.”
...malle se unum civem servare quam mille hostes occidere.
According to the Historia Augusta (fourth century), Roman emperor Antoninus Pius often repeated this saying of Scipio ("Antoninus Pius", 9.10); no earlier attribution to Scipio (or mention of the dictum itself, for that matter) is known.
Disputed
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Scipio Africanus 3
Roman general in the Second Punic War -235–-183 BCRelated quotes

Some historians have opined that the assassination quip was in response to an assassination threat Lincoln had been notified about earlier.
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“An enemy forgiven is more dangerous than a thousand foes.”
Quoted in "The Suez Canal in World Affairs" - Page 79 - by Hugh Joseph Schonfield - 1952