The Book of Characteristics · Hadith 1140 (#Ḥadīth #4)
Chapter 5 | What Has Come About the 21st and 23rd Nights of Ramazan
20-8 حدثنا أبي رضي الله عنه قال: حدثنا سعد بن عبد الله، عن أحمد بن محمد ابن عيسى، عن علي بن الحكم، عن سيف بن عميرة، عن حسان بن مهران، عن أبي عبد الله عليه السلام قال: سألته، عن ليلة القدر فقال: التمسها ليلة إحدى وعشرين وليلة ثلاث وعشرين
20-8 (The compiler of the book narrated) that his father - may God be pleased with him - narrated that Sa’ed ibn Abdullah quoted Ahmad ibn Muhammad ibn Isa, on the authority of Ali ibn al-Hikam, on the authority of Sayf ibn Umayrih, on the authority of Hisan ibn Mihran, “I asked Aba Abdullah as-Sadiq (MGB) about the Night of Power. The Imam (MGB) said, ‘Seek it on the nights of the twenty-first and the twenty-third of Ramazan.’”
Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).