Ahmed bin 'Ubda bin Musa أحمد بن عبدة بن موسى · The Book on Hajj

"A man stood and said 'O Messenger of Allah! What clothing do you command us to wear in Al-Haram?' The Messenger of Allah said: 'Do not wear shirts, nor pants, nor burnooses, nor turbans, nor Khuff - unless one does not have any sandals, then let him wear Khuff, but let him cut them below the ankles. And do not wear any cloth that has been touched by saffron or Wars. And the woman in Ihram is not to cover…

"I saw the Messenger of Allah stoning the Jimar with what was similar to pebbles for Al-Khadhaf."

The Prophet was asked about whether Umrah was obligatory? He said: "No. But if you perform Umrah it is more virtuous."