Musannaf Ibn Abi Shaybah

Hazrat Ali (may Allah be pleased with him) bin Bazimah narrates, he says: I saw Hazrat Umar bin Abdul Aziz in Madinah. He was the best dressed of all, wore the finest fragrance, and was the most graceful in his walk. Then, after that, I saw him walking like monks. So, if anyone tells you that a person's walk is a natural habit, do not believe him after (seeing the example of) Umar bin Abdul Aziz.