The reciter: Abu Bakr ibn Abi Shaybah, Zuhayr ibn Harb, Ibn Numayr, Abu Sa'id, and Uthman narrated to us, and their wordings are similar. They said: Ibn Fudayl narrated to us, al-A'mash narrated to us, from Ibrahim, from Alqamah, from Abdullah, who said:
We used to greet the Prophet while he was engaged in prayer and he would respond to our greeting, but when we returned from the Negus* we greeted him and he did not respond to us, so we said, “Messenger of God, we used to greet you when you were engaged in prayer and you would respond to us.” He replied, “Prayer demands one’s whole attention.”
كنا نسلم على رسول الله صلى الله عليه وسلم وهو في الصلاة فيرد علينا فلما رجعنا من عند النجاشي سلمنا عليه فلم يرد علينا فقلنا يا رسول الله كنا نسلم عليك في الصلاة فترد علينا فقال : إن في الصلاة شغلا Mishkat al-Masabih 979.