Bulugh al-Maram 1376
Narrated Abu Hurairah (RA):
Allah's Messenger (ﷺ) said: "Your oath will be about that matter which your adversary has required you to swear about so that he will believe you."

In another narration: "An oath is to be interpreted according to the intention of the one who requested it (Al-Mustahlif)."

[Muslim reported both narrations].
وَعَنْ أَبِي هُرَيْرَةَ ‏- رضى الله عنه ‏- قَالَ: قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{ " يَمِينُكَ عَلَى مَا يُصَدِّقُكَ بِهِ صَاحِبُكَ" }  وَفِي رِوَايَةٍ: { "اَلْيَمِينُ عَلَى نِيَّةِ اَلْمُسْتَحْلِفِ" }  أَخْرَجَهُمَا مُسْلِمٌ  1‏ .‏‏1 ‏- صحيح رواه مسلم ( 1653 )‏.‏