[Tzqowwyt]

فقال ناس لسعد بن عبادة يا أبا ثابت قد نزلت الحدود لو أنك وجدت مع امرأتك رجلا كيف كنت صانعا قال كنت ضاربهما بالسيف حتى يسكتا أفأنا أذهب فأجمع أربعة شهداء فإلى ذلك قد قضى الحاجة فانطلقوا فاجتمعوا عند رسول الله صلى الله عليه وسلم فقالوا يا رسول الله ألم تر إلى أبي ثابت قال كذا وكذا فقال رسول الله صلى الله عليه وسلم كفى بالسيف شاهدا
ثم قال لا لا أخاف أن يتتابع فيها السكران والغيران
The people said to Sa'd ibn Ubadah: Abu Thabit, the prescribed punishments have been revealed: if you find a man with your wife, what will you do? He said: I shall strike them with a sword so much that they become silent (i.e. die). Should I go and gather four witnesses? Until that (time) the need would be fulfilled.
So they went away and gathered with the Apostle of Allah (peace be upon him) and said: Apostle of Allah! did you not see Abu Thabit. He said so-and-so. The Apostle of Allah (peace be upon him) said: The sword is a sufficient witness. He then said: No, no, a furious and a jealous man may follow this course. [Sunan Abi Daud]

A truly honorable man who possesses gheerah, if he sees his wife with another man will kill them both, he will not even bother to gather witnesses, etc. And the Prophet صلى الله عليه وسلم approved of this. This is the type of "honor killing" which is Islamic.