Al-Tabari narrates in Tārīkh’l-Tabari (4/72):
Fātimah the wife of ‘Umar b. ‘Abd’l-‘Azīz said about his illness, “That night, his shivering became uncontrollable and he couldn’t sleep, so we kept a vigil over him and didn’t sleep either. In the morning, I told a servant of his known as Marthad, “O Marthad, stay with the Amīr’l-Mu’minīn and if he has any single need then at least you are at hand.”
We left and fell into a deep sleep due to the previous night spent awake. It was well into the day once we awoke and we went to see (‘Umar) and found Marthad sleeping outside the house. I woke him up and said, “What are you doing outside Marthad?!”
Marthad replied, “He told me to get out! He said to me, “Marthad, leave me! By Allāh, I see something which is neither human or jinn!”
When I came out, I heard him recite:
تِلْكَ الدَّارُ الْآَخِرَةُ نَجْعَلُهَا لِلَّذِينَ لَا يُرِيدُونَ عُلُوًّا فِي الْأَرْضِ وَلَا فَسَادًا وَالْعَاقِبَةُ لِلْمُتَّقِينَ
We grant the Home in the Hereafter to those who do not seek superiority on earth or spread corruption: the happy ending is awarded to those who are mindful of God. (al-Qasas, 83)
So I entered the room again and I saw his face turned and his eyes were closed. He had passed away.””
May Allāh have mercy upon him.
Fatimah, the wife of Umar ibn Abdil Aziz[Rahimahullah]: I never saw anyone that would pray ﻤمand fast as much as him. Nor did I see anyone that had as much fear as him. After Isha he would just sit and cry until sleep would overcome him. And in the middle of the night he would wake up and start crying again until sleep would overcome him. Sometimes he would be in bed and think about a matter to do with the akhirah and start shaking like a bird that shakes off water.
[‘Uluuw al Himmah]