Al-Kāfi - Volume 1 > Tacit and Explicit Testimony as proof of al-Hassan ibn Ali’s (a.s.) (a.s.) Divine Authority over the people after Amir al-Mu’minin Ali (a.s.)
Hadith #3

3ـ عِدَّةٌ مِنْ أَصْحَابِنَا عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنْ عَلِيِّ بْنِ الْحَكَمِ عَنْ سَيْفِ بْنِ عَمِيرَةَ عَنْ أَبِي بَكْرٍ الْحَضْرَمِيِّ قَالَ حَدَّثَنِي الاجْلَحُ وَسَلَمَةُ بْنُ كُهَيْلٍ وَدَاوُدُ بْنُ أَبِي يَزِيدَ وَزَيْدٌ الْيَمَامِيُّ قَالُوا حَدَّثَنَا شَهْرُ بْنُ حَوْشَبٍ أَنَّ عَلِيّاً (عَلَيْهِ السَّلام) حِينَ سَارَ إِلَى الْكُوفَةِ اسْتَوْدَعَ أُمَّ سَلَمَةَ كُتُبَهُ وَالْوَصِيَّةَ فَلَمَّا رَجَعَ الْحَسَنُ (عَلَيْهِ السَّلام) دَفَعَتْهَا إِلَيْهِ.

3. A number of our people has narrated from Ahmad ibn Muhammad from Ali ibn al-Hakam from Sayf ibn ‘Amayra from abu Bakr al-Hadrami who has said that al-Ajlah, Salamah ibn Kuhayl, Dawud ibn abu Yazid and Zayd al-Yamami from Shahr ibn Hawshab who has said the following. “When Amir al-Mu’minin Ali (a.s.) was about to leave for Kufa he left in ’Umm Salama’s trust his books and his will. When al-Hassan (a.s.) returned to Madina she delivered all of them to him.” The above hadith is as follows in the book of al-Safwan: