Albrecht Dürer was a German painter and mathematician who is often considered the greatest artist of the Northern Renaissance. In the early 16th century he was commissioned to create an altarpiece based on the Assumption of Mary. Unfortunately the altarpiece was destroyed in a fire, but a copy survives, as do many of his preliminary sketches. One of these, the Praying Hands (here turned into a LEGO sculpture by Raphael Heusser) has been repeatedly reproduced and gained popularity. I'm guessing from looking at the copy of the altarpiece that these hands were to become those of the martyred figure in the left-hand panel.