Quran 3:75

وَمِنۡ أَهۡلِ ٱلۡكِتَـٰبِ مَنۡ إِن تَأۡمَنۡهُ بِقِنطَارٍ۬ يُؤَدِّهِۦۤ إِلَيۡكَ وَمِنۡهُم مَّنۡ إِن تَأۡمَنۡهُ بِدِينَارٍ۬ لَّا يُؤَدِّهِۦۤ إِلَيۡكَ إِلَّا مَا دُمۡتَ عَلَيۡهِ قَآٮِٕمً۬ا‌ۗ ذَٲلِكَ بِأَنَّهُمۡ قَالُواْ لَيۡسَ عَلَيۡنَا فِى ٱلۡأُمِّيِّـۧنَ سَبِيلٌ۬ وَيَقُولُونَ عَلَى ٱللهِ ٱلۡكَذِبَ وَهُمۡ يَعۡلَمُونَ ٧٥

Some followers of the scripture can be trusted with a whole lot, and they will give it back to you. Others among them cannot be trusted with a single dinar; they will not repay you unless you keep after them. That is because they say, "We do not have to be honest when dealing with the gentiles!" Thus, they attribute lies to ALLAH, knowingly.