ENOfficial
This hadith has been narrated on the authority of Sufyan with the same chain of transmitters in which it is said:" Fasting of two months."
Source: sunnah.com
Other translations
Arabic
وَحَدَّثَنِيهِ إِسْحَاقُ بْنُ مَنْصُورٍ، أَخْبَرَنَا عُبَيْدُ اللَّهِ بْنُ مُوسَى، عَنْ سُفْيَانَ، بِهَذَا الإِسْنَادِ وَقَالَ صَوْمُ شَهْرَيْنِ .
sunnah.com