Al-Kāfi - Volume 3 > Construction of the Masjid of the Holy Prophet
Hadith #2

2ـ عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُمَيْرٍ عَنْ حَمَّادِ بْنِ عِيسَى عَنِ الْحَلَبِيِّ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ الْسَّلام) قَالَ سَأَلْتُهُ عَنِ الْمَسْجِدِ الَّذِي أُسِّسَ عَلَى التَّقْوَى قَالَ مَسْجِدُ قُبَا.

2. Ali ibn Ibrahim has narrated from his father from ibn abu ‘Umayr from Hammad ibn ‘Isa from al-Halabiy who has said the following: “I asked abu ‘Abd Allah, ‘Alayhi al-Salam, about the Masjid which was built for a pious purpose. He (the Imam) replied, ‘It is Masjid al-Quba””