Ibn Abbas reported that some Muslims met a person with a small flock of sheep. He said:
As-Salam-o-'Alaikum. They caught hold of him and killed him and took possession of his flock. Then this verse was revealed:" He who meets you and extends you salutations, don't say: You are not a Muslim" (iv. 94). Ibn 'Abbas, however, recited the word as-Salam instead of" as-Salam". (AR)
Reference (AR): Sahih Muslim 3025 (AR)
In-book reference (AR): Book 56, Hadith 26 (AR)
USC-MSA web (English) reference(deprecated numbering scheme): Book 43, Hadith 7176 (AR)