Reference: Siyar A’laam an-Nubalaa – Volume 11, Page 33
When Ahmad ibn Harb would sit before the barber to have his moustache trimmed, he would engage in the glorification of Allaah. So the barber would say to him: Can you just shutup for a while! And he would respond: You just do your job [and leave me to my remembrance of Allaah].
