Sunnan Abu Dawud Collection :: Book Number 3
3.0927
Narrated Abdullah ibn Umar: The Apostle of Allah (peace_be_upon_him) went to Quba to offer prayer. Then the Ansar (the Helpers) came to him and gave him a salutation while he was engaged in prayer. I asked Bilal: How did you find the Apostle of Allah (peace_be_upon_him) responding to them when they gave him a salutation while he was engaged in prayer. He replied: In this way, and Ja'far ibn Awn demonstrated by spreading his palm, and keeping its inner side below and its back side above.