History of Khulafah Rashideen by Jalal ad-Din as-Suyuti - translated by Abdassamad Clarke

Ibn cAsakir narrated that cAli said: I don’t know of anyone who didn’t emigrate in secret except for cUmar ibn al-Khattab; because when he wanted to emigrate he strapped on his sword, put his bow over his shoulder, carried his arrows in his hand, and came to the Kacbah where the nobles of Quraysh were in the courtyard.

He performed seven circuits, and then prayed two rakcfat at th< Station (of Ibrahim). Then he approached their circle one step al a time and said, “What ugly faces! Whoever wishes to bereave ha mother, orphan his children and widow his wife then let him meet me behind this valley.” Not one of them followed him. ] He narrated that al-Bara’, may Allah be pleased with him, said* The first of the Muhajirun who came to us was Muscab ibn cUmayr, then Ibn Umm Maktum, then cUmar ibn al-Khattab mounted among twenty others. We said, ‘What has the Messenger of Allah, may Allah bless him and grant him peace, done?’ He said, ‘He is right behind me.’ Then later, the Prophet, may Allah bless him and grant him peace, came and Abu Bakr, may Allah be pleased witli him, along with him.

An-Nawawi said: cUmar attended, along with the Messenger of Allah, may Allah bless him and grant him peace, all of the battles, and he was one of those who stood firm beside him on the Day of Uhud.