The Sufficient (Vol 3) · Hadith 695 (#Ḥadīth #5)
Chapter 52 | Reason for Five Takbir in Salah (Prayer) for a Dead Person
5ـ عِدَّةٌ مِنْ أَصْحَابِنَا عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنْ عَلِيِّ بْنِ الْحَكَمِ عَنْ عُثْمَانَ بْنِ عَبْدِ الْمَلِكِ الْحَضْرَمِيِّ عَنْ أَبِي بَكْرٍ الْحَضْرَمِيِّ قَالَ قَالَ أَبُو جَعْفَرٍ (عَلَيْهِ الْسَّلام) يَا أَبَا بَكْرٍ تَدْرِي كَمِ الصَّلاَةُ عَلَى الْمَيِّتِ قُلْتُ لاَ قَالَ خَمْسُ تَكْبِيرَاتٍ فَتَدْرِي مِنْ أَيْنَ أُخِذَتِ الْخَمْسُ قُلْتُ لاَ قَالَ أُخِذَتِ الْخَمْسُ تَكْبِيرَاتٍ مِنَ الْخَمْسِ صَلَوَاتٍ مِنْ كُلِّ صَلاَةٍ تَكْبِيرَةٌ.
5. A number of our people have narrated from Ahmad ibn Muhammad from Ali ibn al-Hakam from ‘Uthman ibn ‘Abd al-Malik al- Hadramiy from abu Bakr al-Hadramiy who has said the following: “Abu Ja’far , once asked, ‘O abu Bakr, do you know how much is Salah (prayer) for a deceased?’ I replied, ‘No, I do not know.’ He (the Imam) said, ‘It is five Takbir (Allah is great beyond description). Do you know from where are they taken?’ I replied, ‘No, I do not know.’ He (the Imam) said, ‘Five Takbir (Allah is great beyond description) are taken from five Salah (prayer), one Takbir from every Salah (prayer).”’
Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).