Mishkat al-Masabih 3775
Al-Ash‘ath b. Qais said:
A Jew and I shared some land and he denied my right, so I took him to the Prophet who asked me whether I had any proof. When I replied that I had none and he told the Jew to swear an oath, I said, “Messenger of God, he will swear an oath and go off with my property.” Then God most high sent down, “Those who barter for a small price God’s covenant and their oaths . . .” (Al-Qur’an, 3:77)

Abu Dawud and Ibn Majah transmitted it.
وَعَن الأشعثِ بنِ قيسٍ قَالَ: كَانَ بَيْنِي وَبَيْنَ رَجُلٍ مِنَ الْيَهُودِ أرضٌ فحَجَدني فَقَدَّمْتُهُ إِلَى النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَ: «أَلَكَ بَيِّنَةٌ؟» قُلْتُ: لَا قَالَ لِلْيَهُودِيِّ: «احْلِفْ» قُلْتُ: يَا رَسُولَ اللَّهِ إِذَنْ يَحْلِفَ وَيَذْهَبَ بِمَالِي فَأَنْزَلَ اللَّهُ تَعَالَى: (إِنَّ الَّذِينَ يشترونَ بعهدِ اللَّهِ وأَيمانِهِم ثمنا قَلِيلا)
الْآيَة. رَوَاهُ أَبُو دَاوُد وَابْن مَاجَه