Shama-il Tirmidhi Chapter 015, Hadith Number 002 (106).

It is related from Hazrat Anas radiyallahu anhu that the Prophet of Allah sallallahu alaihe wasallam, when entering Makkah as a conqueror, wore a helmet on his auspicious head. After he had removed it, a person came and said, "O' Messenger of Allah, Ibn Khatl is clinging to the cover of the Ka'bah."

The Prophet of Allah sallallahu alaihe wasallam replied, "He is not of the ones who have been granted amnesty, kill him."

Ibn Shihaab Zuhri says, "I have been informed that the Prophet of Allah sallallahu alaihe wasallam was not in the state of Ihraam."

Commentary.
The last sentence in the above hadith by Imam Zuhri refers to a fiqhi mas'alah. According to the Hanafi's it is not permissible to enter Makkah Mukarramah without Ihraam, because it is mentioned in the hadith that it is not permissible to cross the meeqaat boundary without wearing Ihraam. On the strength of the above hadith the Shafi'is say it is permissible. According to the Hanafi's this hadith cannot be used as an argument, because the prohibition was specially lifted for the Prophet of Allah sallallahu alaihe wasallam on this particular occasion. Imam Bukhari and others have quoted narrations wherein the Prophet of Allah sallallahu alaihe wasallam has said, "This was permissible for me today (not wearing Ihraam) and not for any other person."

It may be possible that Ibn Khatl went to hold the cover of the Ka'bah to repent and make supplications, since he knew that there was no amnesty for him. He remembered all his past deeds, turning apostate, and all that he had committed since. He may have done this to make a supplication, as these people also venerated and respected the Ka'bah. The simplest explanation seems to be that according to the old custom, he may have hoped for an amnesty, because of the sanctity and reverence for the Ka'bah, criminals were not killed in this state.