Sunan Ibn Majah — Establishing the Prayer and the Sunnah Regarding Them — Hadith No: 1107
Translation
‘Abdur-Rahman bin Sa’d bin ‘Ammar bin Sa’d narrated that his father told him, from his father, from his grandfather, that when the Messenger of Allah (ﷺ) delivered a speech on the battlefield he would do so leaning on a bow, and when he delivered a sermon on Friday, he would do so leaning on his staff