Sunan an-Nasa'i 4461
سنن النسائي#4461Sahihأَخْبَرَنَا أَحْمَدُ بْنُ عَمْرِو بْنِ السَّرْحِ، قَالَ حَدَّثَنَا ابْنُ وَهْبٍ، عَنْ يُونُسَ، عَنِ ابْنِ شِهَابٍ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " الْحَلِفُ مَنْفَقَةٌ لِلسِّلْعَةِ مَمْحَقَةٌ لِلْكَسْبِ " .
It was narrated from Abu Hurairah that the Prophet said:"Taking oaths may help you to make a sale but it takes (blessing) away from the earnings "(Sahih)
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Abu GhuddahSahih
Al-AlbaniSahih Hadith
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 44:13