Ibn ‘Abbas told that the Prophet (ﷺ) said to a man whom he had asked to take an oath, “Swear by God than Whom there is no god that you have nothing belonging to him,” i.e. the plaintiff. Abu Dawud transmitted it.

وَعَنِ ابْنِ عَبَّاسٍ: أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ لِرَجُلٍ حَلَّفَهُ: «احْلِفْ بِاللَّهِ الَّذِي لَا إِلَهَ إِلَّا هُوَ مَاله عِنْدَكَ شَيْءٌ» يُعْنَى لِلْمُدَّعِي. رَوَاهُ أَبُو دَاوُدَ