An Etymological Dictionary of the German Language/Annotated/Sold
Sold, masculine, ‘pay, salary,’ from Middle High German solt (d), masculine, ‘reward for service done,’ also ‘that which is to be performed, duty, service.’ It first appears in Middle High German about 1200 A.D., and is derived from French solde, ‘soldier's pay,’ which is properly the coin, Latin solidus, Italian soldo (Modern French sou); yet the double sense in Middle High German can only be explained by the influence of the verb sollen. —