it was narrated from Qatada regarding Allah’s saying ” O you who have believed, indeed the polytheists ( non-Muslims ) are impure ” ( Quran 9:28 ) , he said that means ritual impurity and which also means they don’t wash and they are impure ! and others said that means ” indeed the polytheists are nothing but filthy pigs and dogs ! and you guys know that most of the times you hear from Muslims calling others ” This is a dog and / or this is a pig ” and they say it specifically to Jews and Christians and also to the rest of the infidels ( non-Muslims ) so , Muslims call non-Muslims ” Pigs and dogs ” so , where did that come from ? and those tenets have impact on the real life ( of Muslims ) and they are not just stories exist in Islam rather , they have a backlash in the actions and behaviors of Muslims against non-Muslims ; so , Muslims calling non-Muslims as pigs and dogs came from that one verse and it was narrated from Al-Hasan regarding that verse ” indeed the polytheists are impure ” , he said ” Don’t shake hands with the polytheists and if anyone shakes hands with them , then they should perform ablution ” and that means if a Muslim shakes hands with a polytheists , then he should wash his hands ! and why is that ? because they ( the polytheists ” non-Muslims ” are filthy and that’s according to the Quran and the interpretations of Muslims ( i.e. Muslim scholars ) ! well , how then will the Muslims deal with the non-Muslims while they think that they are filthy , pigs and dogs ?