It is narrated from Sayyiduna Wathilah bin al-Asqa' (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The scriptures of Ibrahim were revealed on the first night of the blessed month of Ramadan; the Torah was revealed when six nights of Ramadan had passed; the Injil (Gospel) was revealed when thirteen nights of Ramadan had passed; the Zabur (Psalms) was revealed when eighteen nights of Ramadan had passed; and the Qur'an was revealed when twenty-four nights of Ramadan had passed."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Qatadah (may Allah have mercy on him) except Imran al-Qattan, and this report is narrated from the Messenger of Allah (peace and blessings be upon him) only through this chain."
Hadith Referenceالمعجم الأوسط / باب العين / 3740
Hadith Takhrij«أخرجه البيهقي فى «السنن الكبرى» برقم: 18721، وأحمد فى «مسنده» برقم: 17258، والطبراني فى «الكبير» برقم: 185»