From where are the pebbles for stoning the pillars taken, and what is their description?

Question: From where are the pebbles for stoning the pillars taken? What is their description, and what is the ruling on washing them?

Answer: The pebbles are taken from Mina. If one takes pebbles from Muzdalifah on the day of the festival, there is nothing wrong with it. There are seven pebbles with which one stones the Pillar of al-'Aqabah on the day of the festival. It is not prescribed to wash them; rather, one takes them from Mina or Muzdalifah and stones with them, or takes them from the rest of the sacred precinct, and that is sufficient with no blame.
During the days of Tashriq, one picks them up from Mina, one and twenty pebbles each day. If one hastens, it is forty-two for the eleventh and twelfth days. If one does not hasten, it is sixty-three. They are pebbles of al-khadhf, resembling the medium-sized dung of sheep, larger than chickpeas and smaller than hazelnuts, as the jurists said. They are called pebbles of al-khadhf, as mentioned previously, slightly smaller than sheep dung.