‘Umar Ibn Al-Khattaab was very protective of the Prophet’s wives. They were all very innocent and pious and yet, as ‘Umar certainly remembered, that did not stop the hypocrite ‘Abdullaah Ibn Ubay from slandering ‘Aa’ishah. Thus, ‘Umar would do everything in his power to safeguard the honour of the Prophet’s wives.
So when the Prophet’s wives asked ‘Umar to perform Hajj, he denied their request. Then, when they continued to implore him for permission, he met them halfway, saying to them: “I will grant you permission to go the following year, and yet even that is something I do not truly agree with.”
The following year,’Umar sent ‘Uthmaan Ibn ‘Affaan and ‘Abdur-Rahmaan Ibn ‘Awf to accompany the Mothers of the believers during their pilgrimage. And ‘Umar gave both of them strict orders; one of them was to walk ahead of the Prophet’s wives, and the other was to walk behind them. They were not to allow anyone to walk alongside the Prophet’s wives. When they had to stop to set up camp, they were to set up camp in a mountain pass (an enclosed area); as long as the Prophet’s wives rested inside the mountain pass, they were to stand guard at the entrance of the mountain pass; they were to allow no one to enter upon the Prophet’s wives.
And when the Prophet’s wives performed Tawaaf around the Ka’bah, they were to forbid all men from performing Tawaaf at the same time.
[Tabaqaat, by Ibn Sa’d, 8/109]