Why should a prophet in islam make a slaughter in the land before taking captives?

Eddie: Why should a prophet in islam make a slaughter in the land before taking captives?
Koran 8:67 It is not for any prophet to have captives until he hath made slaughter in the land. Ye desire the lure of this world and Allah desireth (for you) the Hereafter, and Allah is Mighty, Wise.

Make a slaughter in the land means killing all, right and left. It´s the demonstration of the “peaceful nature of islam” – or a warning to the non-Muslims about what expects them?

Answers and Views:

Answer by Arturo
Because he is a prophet of ISLAM, the most aggressive among all the three very aggressive monotheistic religions.

Answer by Samsom .
Making slaughter also means killing enemies. Killing all, right and left, is not allowed in Islam, that is only allowed according to the corrupted Bible.
Do not spare them; put to death men and women, children and infants, cattle and sheep, camels and donkeys.’ ”
Samuel 15:2,3

Quran doesn’t say that. Read the laws of Jihad here:

Read more how Islamophobes take Quran out of context:

Answer by trancinguy
First of all, it is القران not “Koran”. Second, —-<٨:٦٧<—-.