"Fight those who believe not in Allah or the Last Day, nor hold that forbidden which hath been forbidden by Allah and His Messenger, nor acknowledge the religion of Truth, (even if they are) of the People of the Book, until they pay the jizya with willing submission, and feel themselves subdued." - Quran 9:29 (read more)

"Narrated Anas: The climate of Medina did not suit some people, so the Prophet ordered them to follow his shepherd, i.e. his camels, and drink their milk and urine (as a medicine). So they followed the shepherd that is the camels and drank their milk and urine till their bodies became healthy. Then they killed the shepherd and drove away the camels. When the news reached the Prophet he sent some people in their pursuit...." - Sahih Bukhari 1:5:268 (read more)

"Allah prohibited His believing servants from becoming supporters of the disbelievers, or to take them as comrades with whom they develop friendships, rather than the believers...Allah said next, (unless you indeed fear a danger from them) meaning, except those believers who in some areas or times fear for their safety from the disbelievers. In this case, such believers are allowed to show friendship to the disbelievers outwardly, but never inwardly." - Ibn Kathir