Al-Kāfi

Hadith 776
mourning-condolence
2ـ عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُمَيْرٍ عَنْ بَعْضِ أَصْحَابِهِ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ الْسَّلام) قَالَ التَّعْزِيَةُ لأَهْلِ الْمُصِيبَةِ بَعْدَ مَا يُدْفَنُ.
2. Ali ibn Ibrahim has narrated from his father from Ibn Abi ‘Umayr from certain persons of his people who has said the following: “Abu ‘Abd Allah (a.s.), has said that condolences should be offered to the people of the deceased after burial takes place.”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī