Al-Kāfi - Volume 7 > A Man Makes a Will and Appoints an Executor but he Refuses to Accept it
Hadith #5

5- عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُمَيْرٍ عَنْ هِشَامِ بْنِ سَالِمٍ عَنْ أَبِي عَبْدِ اللهِ (عَلَيْهِ السَّلام) فِي الرَّجُلِ يُوصِي إِلَى رَجُلٍ بِوَصِيَّةٍ فَيَكْرَهُ أَنْ يَقْبَلَهَا فَقَالَ أَبُو عَبْدِ اللهِ (عَلَيْهِ السَّلام) لا يَخْذُلْهُ عَلَى هَذِهِ الْحَالِ.

5. Ali ibn Ibrahim has narrated from his father from ibn abu ‘Umayr from Flisham ibn Salim who has narrated the following: “About the case of a man who is appointed as the executor in a will but he dislikes it, abu ‘Abd Allah, ‘Alayhi al-Salam, has said, ‘He must not betray him in such condition.’”