[adolfadsermens]

Sorry Maulana Saheb in thinking you were asking about any incidents of i'itikaaf. Here is another narration that I have found. I am unsure as to the authenticity of it. I have also myself not looked up the hadith. You are more qualified than me to look it up.

It clearly mentions Hadhrat Abdullah Ibn Abbas carrying out I'itikaaf following the death of Rasulullah

Hadith No 1

Ibn Abbas R.A. reports that while he was once performing I’itikaaf in the musjidun Nabwi (Rasulullah’s musjid), a certain man came to him, greated him and sat down. Ibn Abbas said to him: “I see that you seem sad and troubled”. The man replied: “Yes, O son of the uncle of Rasulullah S.W., I am indeed troubled in that I have an obligation to fulfill to someone. I swear by the holiness of the inmate of this honoured resting place (Rasulullah’s grave S.W.) that I am not able to fulfill this obligation”. Ibn Abbas R.A. inquired: “Shall I intercede with that person on your behalf?” the man replied: By all means if you so wish”. Ibn Abbas put on this shoes and proceeded from the Musjid. The man seeing this said: “Have you then forgotten that you are in I’itikaaf?” With tears filling his eyes Ibn Abbas R.A. replied: “No, the time is still fresh in my mind, I heard the esteemed master of this tomb Rasulullah S.W. say, “Whoever sets forth in the way and makes an effort of settling a necessary affair on behalf of his brother, that service shall be better for him than to perform I’itikaaf for ten years, and whomsoever performs I’itikaaf for a day, thereby seeking the pleasure of Allah, Allah will open three trenches between him and the fire of hell, the width of each being the distance between heaven and earth”.
Reported by ‘Tabraani in Al Awsa’t.

Hadith No 2