"You shall not stand [idly] by the blood of your neighbor"—Leviticus 19:16.
It is forbidden to abstain from offering assistance when perceiving one's fellow in mortal danger, or his property in danger of destruction.
Examples: One who knows how to swim who sees his fellow drowning, must jump into the water to save him; if one becomes aware of a plot against another's life, it is his responsibility to attempt to thwart it; one who has evidence that could support his fellow's monetary claim in court, must come forward and testify.
