A pungent herb (Ruta graveolens) used in cooking and medicine. Jesus mentioned it when rebuking the Pharisees for tithing herbs while neglecting justice and love.
Jesus said: 'Woe to you Pharisees, because you give God a tenth of your mint, rue and all other kinds of garden herbs, but you neglect justice and the love of God' (Luke 11:42). Meticulous religious observance without justice and love is spiritual hypocrisy. God cares more about character than calculations.