How did the Prophet ﷺ respond to them when they would greet him with salaam while he was praying? He said, "He would gesture with his hand."
حدثنا محمود بن غيلان حدثنا وكيع حدثنا هشام بن سعد عن نافع عن ابن عمر قال
كيف كان النبي ﷺ يرد عليهم حين كانوا يسلمون عليه وهو في الصلاة قال كان يشير بيده
[Its chain is hasan]. Abu Dawud reported it in the Book of Prayer, Chapter on Returning the Greeting during Prayer, hadith 927, from the hadith of Hisham bin Saad with this chain, and Ibn Jarud graded it sahih, hadith 215. As for the hadith of Zayd bin Aslam, Ibn Majah reported it, hadith 1017, that he heard it from Ibn Umar , as is found in Sahih Ibn Khuzayma.