Al-Walid bin Qays said that Abdullah bin Mas'ud (may Allah be pleased with him) ascended the pulpit, intending to announce the death of Umar (may Allah be pleased with him), and he was overcome by tears once or twice. Then he said: "Umar bin al-Khattab (may Allah be pleased with him) was a strong fortress for Islam; whoever entered it would enter and not leave it, and now that fortress has collapsed." Then he announced his death, and then said: "And Uthman bin Affan (may Allah be pleased with him) has been made Caliph, and we did not fall short in choosing the best person."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 8812