Al-Kāfi

Hadith 2121
dua
10ـ أَبُو عَلِيٍّ الأشْعَرِيُّ عَنْ مُحَمَّدِ بْنِ سَالِمٍ عَنْ أَحْمَدَ بْنِ النَّضْرِ عَنْ عَمْرِو بْنِ شِمْرٍ عَنْ جَابِرٍ عَنْ أَبِي جَعْفَرٍ (عَلَيهِ السَّلام) قَالَ لِكُلِّ شَيْ‏ءٍ رَبِيعٌ وَرَبِيعُ الْقُرْآنِ شَهْرُ رَمَضَانَ.
10. Abu Ali al-Ash’ari has narrated from Muhammad ibn Salim from Ahmad ibn al- Nadr from ‘Amr ibn Shimr from Jabir from abu Ja’far (a.s.) who has said the following: “Abu Ja’far (a.s.) has said, ‘For everything there is a spring. The spring for the Holy Quran is the month of Ramadan.’”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī