(2) Umat Islam sepakat bahwa berpuasa di bulan Ramadhan hukumnya wajib, dan dalilnya terdapat dalam Al-Qur'an serta Sunnah. Allah berfirman (terjemahan makna):

(2) The ummah is agreed that fasting the month of Ramadaan is obligatory, the evidence for which is in the Qur’aan and Sunnah. Allaah says (interpretation of the meaning):

“Wahai orang-orang yang beriman! Diwajibkan atas kamu berpuasa sebagaimana diwajibkan atas orang-orang sebelum kamu, agar kamu bertakwa.” {Al-Baqarah 2:183} Nabi ﷺ bersabda: “Islam dibangun atas lima [perkara]…” di antaranya beliau menyebutkan puasa Ramadan. (Diriwayatkan oleh al-Bukhari, al-Fath, 1/49). Siapa pun yang membatalkan puasa di bulan Ramadan tanpa uzur yang dibenarkan, berarti telah melakukan dosa besar yang berat. Nabi ﷺ bersabda, menceritakan mimpi yang beliau lihat: “… hingga aku sampai di gunung, di sana aku mendengar suara-suara keras. Aku bertanya, ‘Suara apa ini?’ Mereka menjawab, ‘Ini adalah lolongan penghuni Neraka.’ Kemudian aku dibawa [ke tempat lain], dan aku melihat orang-orang tergantung pada urat kaki mereka, dengan sudut mulut mereka robek dan menetes darah. Aku bertanya, ‘Siapakah mereka ini?’ Mereka menjawab, ‘Orang-orang yang berbuka puasa sebelum waktunya tiba,’ yaitu sebelum waktu iftar.” (Saheeh al-Targheeb, 1/420).

“O you who believe! Observing al-sawn (the fasting) is prescribed for you as it was prescribed for those before you, that you may become al-muttaqoon (the pious).” [al Baqarah 2:183] The Prophet (peace and blessings of Allaah be upon him) said: “Islam is built on five [pillars]…” among which he mentioned fasting in Ramadaan. (Reported by al-Bukhaari, al Fath, 1/49). Whoever breaks the fast during Ramadaan without a legitimate excuse has committed a serious major sin, The Prophet (peace and blessings of Allaah be upon him) said, describing a dream that he had seen: “… until I was at the mountain, where I heard loud voices. I asked, ‘What are these voices?’ They said, ‘This is the howling of the people of Hellfire.’ Then I was taken [to another place], and I saw people hanging from their hamstrings, with the corners of their mouths torn and dripping with blood. I said, ‘Who are these?’ They said, ‘The people who broke their fast before it was the proper time to do so,’ i.e., before the time of iftaar.” (Saheeh al-Targheeb, 1/420).

Al-Haafiz al-Dhahabi (semoga Allah merahmatinya) berkata, “Di kalangan kaum Muslimin telah dikenal luas bahwa siapa pun yang tidak berpuasa di bulan Ramadhan tanpa uzur yang sah, lebih buruk daripada seorang pezina atau peminum khamr; mereka meragukan apakah ia masih seorang Muslim sama sekali, dan mereka menganggapnya sebagai seorang ahli bid'ah dan orang fasik.” Syaikhul Islam [Ibnu Taimiyah] (semoga Allah merahmatinya) berkata: “Jika seseorang tidak berpuasa di bulan Ramadhan dengan mengetahui bahwa hal itu haram, tetapi menghalalkannya bagi dirinya sendiri, maka bunuhlah dia; dan jika ia melakukannya karena kefasikan [namun meyakini bahwa itu haram], maka hukumlah dia karena tidak berpuasa.” (Majmu' al-Fatawa, 25/265).

Al-Haafiz al-Dhahabi (may Allaah have mercy on him) said, “Among the believers it is well-established that whoever does not fast in Ramadaan without a valid excuse is worse than an adulterer or drunkard; they doubt whether he is even a Muslim at all, and they regard him as a heretic and profligate.” Shaykh al-Islam [Ibn Taymiyah] (may Allaah have mercy on him) said: “If a person does not fast in Ramadaan knowing that it is haraam but making it halaal for himself to do so, kill him; and if he does it because he is immoral [but believes it is haraam], then punish him for not fasting.” (Majmoo’ al-Fataawa, 25/265).