Furthermore, Sayyiduna Ibraheem Bin Adham رَحْمَةُ اللهِ تَعَالٰی عَلَيْه has said: The more difficult a good deed will be in the world, the heavier it will be on the scale of good deeds on the Day of Judgement.
. (Tazkira-tul-Awliya, pp. 95)
Sayyiduna ‘Usman-e-Ghani رَضِىَ اللهُ تَعَالٰی عَـنْهُ would always observe Nafl fasts. Having taken rest during the initial part of the night, he رَضِىَ اللهُ تَعَالٰی عَـنْهُ would spend the rest of the night for Qiyam (worship).
. (Musannaf Ibn Abi Shaybah, vol. 2, pp. 173, Raqm 6)
Observed fasts continuously for forty years
Sayyiduna Dawood Taa`ee رَحْمَةُ اللهِ تَعَالٰی عَلَيْه observed fasts continuously for forty years. He رَحْمَةُ اللهِ تَعَالٰی عَلَيْه was so sincere in his worship that he رَحْمَةُ اللهِ تَعَالٰی عَلَيْه would not even let his family know about his fasts. While going to work he رَحْمَةُ اللهِ تَعَالٰی عَلَيْه would take lunch with him and give it to someone on his way. After Maghrib, he رَحْمَةُ اللهِ تَعَالٰی عَلَيْه would return home and eat food/p>
(Ma’dan-e-Akhlaq, part 1, pp. 182)
Fasted throughout the day and worship throughout the night for 60 years
Sayyiduna Mansoor Bin Mu’tamir رَحْمَةُ اللهِ تَعَالٰی عَلَيْه spent 60 years worshipping at night and fasting in the day.
(152 Rahmat Bhari Hikayaat, pp. 78)
Would fast after a gap of one day
Sayyiduna ‘Allamah Shaykh ‘Imaaduddin رَحْمَةُ اللهِ تَعَالٰی عَلَيْه was a great jurist and Mufti. He رَحْمَةُ اللهِ تَعَالٰی عَلَيْه was a great worshipper and a pious person. He رَحْمَةُ اللهِ تَعَالٰی عَلَيْه would observe Nafl fasts and offer Nafl Salah abundantly. He رَحْمَةُ اللهِ تَعَالٰی عَلَيْه would observe a fast after one day gap.
(152 Rahmat Bhari Hikayaat, pp. 260)
Due to excess of fasts his back got bent
Sayyiduna ‘Isa Bin Zaazaan Ubulli رَحْمَةُ اللهِ تَعَالٰی عَلَيْه used to observe fasts abundantly due to which his back became bent and he رَحْمَةُ اللهِ تَعَالٰی عَلَيْه lost his voice.
(152 Rahmat-Bhari Hikayaat, pp. 272)
How enthusiastic our pious saints رَحِمَهُمُ الـلّٰـهُ تَـعَالٰی had been that they observed fasts for 40 years, 60 years, or rather some observed fasts throughout their lives. The state of their sincerity was that they did not use to inform their family members about their fasts. Therefore, we should also observe the Nafl fasts of Rajab-ul-Murajjab, Sha’ban-ul-Mu’azzam, Shash Eid (six fasts after Eid-ul-Fitr), Monday, Thursday and days of Bayd (i.e. 13, 14, 15 of the Madani month) etc. in addition to the mandatory fasts of blessed Ramadan as Nafl fasts also have lots of excellences. The Prophet of Rahmah, the Intercessor of the Ummah صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم has stated: If someone observes a Nafl fast and (even if he) is given the whole earth full of gold (as a reward) his reward will still remain incomplete, he will be given his reward on the Day of Judgement only.
(Musnad Abi Ya’la, vol. 5, pp. 353, Hadees 6104)