All you need to about Rukan Yamani (The Yemeni Corner) of the Ka’bah 

This corner of the Ka’bah is called the Rukan Yamani because it is situated on the side of the Ka’bah which faces the land of Yemen. It is on the wall opposite to that of the Hajar al-Aswad.

Making ‘Istilaam’ of the Rukan Yamani

• Because this corner is still standing on the foundation that Ebrahim (عليه السلام) built, the narration of Abdullah bin Abbas (رضي الله عنه) states that the Prophet (ﷺ) made ‘Istilaam’ of it.
• ‘Istilaam’ refers to the touching of the corner whether this is done by hand or by kissing. As the Prophet (ﷺ) touched the Rukan Yamani by hand, this practise is Sunnah. However, there is no harm if one is unable to touch it due to the crowds.

The Rukan Yamani fully exposed

• It was the practice of the Prophet (ﷺ) that when he passed between the Rukan Yamani and the Hajar al-Aswad, he recited the following du’a: “O Rabb, grant us (all that which is) good in this world, (all that which is) good in the Aakhirah and save us from the punishment of the fire (of Jahannam).” [Surah Baqarah, verse 201]
• It was the practice of the Prophet (ﷺ) that when he passed between the Rukan Yamani and the Hajar al-Aswad, he recited the following du’a: “O Rabb, grant us (all that which is) good in this world, (all that which is) good in the Aakhirah and save us from the punishment of the fire (of Jahannam).” [Surah Baqarah, verse 201]

Source: Islamiclandmark