It was narrated from Ibn 'Abbas that the Messenger of Allah ﷺ said:
“If the people were given what they claimed, some would have claimed the lives and property of men. But the one the claim is made against is obliged to swear an oath.”

حَدَّثَنَا حَرْمَلَةُ بْنُ يَحْيَى الْمِصْرِيُّ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ وَهْبٍ، أَنْبَأَنَا ابْنُ جُرَيْجٍ، عَنِ ابْنِ أَبِي مُلَيْكَةَ، عَنِ ابْنِ عَبَّاسٍ، أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ " لَوْ يُعْطَى النَّاسُ بِدَعْوَاهُمُ ادَّعَى نَاسٌ دِمَاءَ رِجَالٍ وَأَمْوَالَهُمْ وَلَكِنِ الْيَمِينُ عَلَى الْمُدَّعَى عَلَيْهِ " .