عَنْ أَبِي الدَّرْدَاءِ رَضِيَ اللَّهُ عَنْهُ قَالَ: أَوْصَانِي خَلِيلِي أَبُو الْقَاسِمِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ بِثَلَاثٍ لَا أَدَعُهُنَّ لِشَيْءٍ أَوْصَانِي بِثَلَاثَةِ أَيَّامٍ مِنْ كُلِّ شَهْرٍ، وَأَنْ لَّا أَنَامَ إِلَّا عَلَى وَتْرٍ وَسُبْحَةِ الضُّحَى فِي الْحَضَرِ وَالسَّفَرِ
It is narrated from Sayyiduna Abu Darda’ (may Allah be pleased with him), he says that my beloved friend Abu al-Qasim (peace and blessings be upon him) advised me regarding three things, which I will never abandon for any reason. The Prophet (peace and blessings be upon him) advised me to fast three days every month, to sleep only after performing the Witr prayer, and to offer the Duha (forenoon) prayer whether at home or on a journey.