Al-Kāfi

Hadith 806
taqiyyah
17ـ مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنِ ابْنِ فَضَّالٍ عَنِ ابْنِ بُكَيْرٍ عَنْ مُحَمَّدِ بْنِ مُسْلِمٍ عَنْ أَبِي عَبْدِ الله (عَلَيهِ السَّلام) قَالَ كُلَّمَا تَقَارَبَ هَذَا الأمْرُ كَانَ أَشَدَّ لِلتَّقِيَّةِ.
17. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from ibn Faddal from ibn Bukayr from Muhammad ibn Muslim from Abu ‘Abdillah (a.s.) who has said the following: “As it (time of Imam al-Mahdi) draws closer, al-Taqiyyah will be more intensely needed.”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī