He performs all five daily prayers there in shortened form, without combining them.
Proceeding to ʿArafah:
61 – When the sun rises on the Day of ʿArafah he heads for ʿArafah, reciting either the talbiyah or the takbīr. Both practices were done by the Prophet’s Companions ﷺ on his Farewell Pilgrimage: some proclaimed the talbiyah and were not rebuked, and others proclaimed the takbīr and were not rebuked.¹
62 – He then stops at Namirah,² a spot just outside the boundary of ʿArafah, and stays there until shortly before the sun passes its zenith.
63 – Once the sun has declined he proceeds to ʿUranah and dismounts there.¹ It lies on the edge of ʿArafah, and there the imam delivers a sermon suited to the occasion.
64 – The imam then leads the people in the ẓuhr and ʿaṣr prayers, shortening and combining them during the time of ẓuhr.
65 – A single adhān is given for both prayers, followed by two separate iqāmahs.
66 – Nothing at all is prayed between the two obligatory prayers.³
67 – Whoever is unable to pray with the imam should offer them in the same manner—shortened and combined—either on his own or with others in the same situation.⁴
(1) Reported by the two Shaykhs, Bukhari and Muslim.
(2) Nowadays it is virtually impossible to stop at this station—and the one that follows—because of the heavy crowds; therefore, if a pilgrim proceeds straight to Arafah there is, God willing, no blame. Shaykh al-Islam Ibn Taymiyyah writes in Majmu al-Fatawa, 26/168: “According to the Sunnah, the Messenger of Allah spent the Day of Tarwiyah in Mina, passed the night there before the Day of Arafah, then remained in Urnah—the area between al-Mashar al-Haram and Arafah—until noon, before moving on to Arafah. On the way he delivered the sermon and combined the two prayers (dhuhr and asr) in the valley of Urnah. The jurists are virtually unanimous on this, although many later writers do not distinguish it and most people are unaware of it because of prevailing innovations.”
(3) I would also note that no authentic report shows him performing voluntary prayers before dhuhr or after asr here—or during any of his journeys. The only supererogatory prayers he is proven to have maintained while travelling are the two rakahs of fajr and the witr.
(4) Related by Bukhari in suspended (muʿallaq) form from Ibn Umar; see Mukhtasar al-Bukhari, 25/89/3.