"The famous Muslim scholar Ibn Kathir's commentary of the verse in his Tafsir is as follows:
Imam Ahmad recorded that `Ikrimah said that Ibn `Abbas said, "A man from Bani Sulaym, who was tending a flock of sheep, passed by some of the Companions of the Prophet and said Salam to them. They said (to each other), `He only said Salam to protect himself from us.' Then they attacked him and killed him."
http://military.wikia.com/wiki/Expedition_of_Abu_Qatadah_ibn_Rab%27i_al-Ansari_(Batn_Edam)
