Know that as “the night of Qadr” has a truth and an inside, it also has a form and an appearance, or even appearances in the world of nature. But as appearances can differ in respect of their shortcomings and perfections, from the narratives and hadiths about specifying "the night of Qadr" can be deduced that all the noble nights specified in those narratives are of the appearances of "the night of Qadr" except that they differ from one another in respect of their honor and perfection of appearance, while that noble night, which is the full appearance of "the night of Qadr" the night of the complete joiningand the perfect attainment of the Last Prophet, is hidden in the whole year, in the blessed month of Ramadan, in its last ten nights or in the "three nights”. The narratives of the Elite and the public also differ. The Elite narrate, with uncertainty, that it is on the nights of the nineteenth, twenty-first and twenty-third of Ramadan, and sometimes they waver between the night of the twenty-first and the twenty-third.
Shihab ibn Abdu Rabbih says: “I asked Imam Sadiq (a.s.) to tell me about "the Night of Qadr”, He said: "the night of the twenty-first and the night of the twenty-third."
Abdul Wahid ibn al-Mukhtar al-Ansari says: "I asked Imam Baqir (a.s) about 'the night of Qadr.' He said: 'it is on two nights: the night of the twenty-third and the night of the twenty-first,' I said: 'Name only one of them.' He said: 'What if you do something on the two nights of which one is 'the Night of Qadr?'" Ibn Abou Ali says: "I asked Imam Sadiq (a.s.) about 'the Night of Qadr'. He said: "Get it on the nineteenth, twenty-first and twenty-third.""
The devotee and pious "Sayyid" in Iqbal says: “Know that it is the night of the twenty-third of the month of Ramadan. There are explicit narratives that it is 'the Night of Qadr' by revelation and declaration. Of that I relate, on my authority up to Sufyan ibn Sit who said: "I asked Imam Sadiq (a.s.) to tell me which was 'the Night of Qadr' exactly." He said: "The night of the twenty-third." Another is to narrate, on my authority up to Zurarah, quoting 'Abdul Wahid ibn Mukhtar Ansari, who said: "I asked Imam Baqir (a.s.) about 'the Night of Qadr.' He said:" By Allah I tell you with no ambiguity, it is the first night of the last seven nights." Zurarah was further quoted to have said that the month which the Imam mentioned had twenty-nine days. After that other narratives are related to the effect that "the Night of Qadr" is the night of the twenty-third of Ramadan, such as the case of Juhani, which is well known.”
Disciplines of the prayer, Text, Page: 443-444