A.T. Robertson Commentary Luke 15:8

"Or what woman having ten pieces of silver, if she lose one piece, doth not light a lamp, and sweep the house, and seek diligently until she find it?" — Luke 15:8 (ASV)

Ten pieces of silver (δραχμας δεκα). The only instance in the N.T. of this old word for a coin of 65.5 grains about the value of the common δηναριυς (about eighteen cents), a quarter of a Jewish shekel. The double drachma (διδραχμον) occurs in the N.T. only in Mt 17:24. The root is from δρασσομα, to grasp with the hand (1 Corinthians 3:19), and so a handful of coin. Ten drachmas would be equal to nearly two dollars, but in purchasing power much more.

Sweep (σαρο). A late colloquial verb σαροω for the earlier σαιρω, to clear by sweeping. Three times in the N.T. (Luke 11:25; Luke 15:8; Matthew 12:44). The house was probably with out windows (only the door for light and hence the lamp lit) and probably also a dirt floor. Hence Bengel says: non sine pulvere. This parable is peculiar to Luke.