Musannaf Ibn Abi Shaybah

Hazrat Abdullah bin Umar (may Allah be pleased with them both) was asked about the Sa’i between Safa and Marwah. He said to the questioner: Start the rounds (Sa’i) from Safa and end at Marwah, and if you fear forgetting the number of rounds, then take small stones or pebbles with you and place one pebble at Safa and another at Marwah (in this way, counting will be easier).