Tahrveg

Tahrveg, the Keen Arrow, is the Minor God of Archery.

In olden days, Tahrveg was a popular God and most archers gave a finger to the God to help their aim. In the last Chaos Incursion, so great was the fear that archers cut off so many fingers they couldn’t hold their bows. Since then, dogma has been changed so that the gift is symbolic and each archer tends to soak his finger in his own urine to ensure that his aim is true. Some maidens giggle and claim it helps their aim when firing their other bow.

Source

 * Warhammer Fantasy RPG 2nd ED -- Tome of Salvation pg. 82