Standing at Arafat

It is narrated from Abdullah bin Sakhbarah (may Allah have mercy on him): I went with Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) from Mina to Arafah. Ibn Mas'ud was a man of wheat-coloured complexion with long locks, and he had the simplicity of the desert people about him. He was calling out the talbiyah in a loud voice, and some ignorant people gathered around him and said: O Bedouin, this is not a day for the talbiyah but for the takbir. At that he turned towards me and said: Have the people become ignorant, or have they forgotten? By the One who sent Muhammad (peace and blessings be upon him) with the truth, I set out with the Messenger of Allah (peace and blessings be upon him) from Mina to Arafah, and he (peace and blessings be upon him) did not stop calling out the talbiyah until he stoned the Jamrah, although he would also mix takbir and tahlil ('La ilaha illallah', there is no god but Allah) into the talbiyah.
This hadith is sahih (authentic) on the condition of Imam Muslim, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Keep away from the valley of Uranah (do not stand there), and also keep away from the valley of Muhassir (do not stay there)."
This hadith is sahih (authentic) on the condition of Imam Muslim, but the two Shaykhs (Bukhari and Muslim) did not record it. It also has an authentic supporting narration (shahid) on the condition of the two Shaykhs, although there is some abridgement in its chain:

It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that he used to say: It used to be said: Keep away from Batn Muhassir, and keep away from Uranat as well. What is meant by Uranat is that during the standing (wuquf) at Arafah one should not stay in the valley of Uranah; and what is meant by Muhassir is that during the stay at Muzdalifah one should not stay in the valley of Muhassir.

It is narrated from Sayyiduna Yazid bin Shayban (may Allah have mercy on him) that: We were standing behind the place of standing (mawqif), when Ibn Mirba' al-Ansari (may Allah be pleased with him) came to us and said: I am the messenger of the Messenger of Allah (peace and blessings be upon him) to you. He (peace and blessings be upon him) says: "Remain at these places of worship of yours (the stations of Hajj), for you are upon the inheritance (the way of Hajj) of your father Ibrahim (peace be upon him)."
This hadith has a sahih (authentic) chain of narration, but the two Shaykhs did not record it.