Bukti kewajibannya terdapat dalam al-Qur'an, sunnah, qiyas dan ijmak.

The evidence of its obligation is in the Qur— ’an, sunna, 7A and ijmfr77.

Dalam Al-Qur'an, Allah Yang Maha Tinggi berfirman: "Wahai orang-orang yang beriman, apabila kamu hendak mengerjakan solat, maka basuhlah muka dan tangan kamu hingga ke siku, sapulah kepala kamu, dan basuhlah kaki kamu hingga ke buku lali,"{26} {27} {28} {29}. Para ahli fikah Islam telah sepakat bahawa mematuhi perintah ini adalah wajib bagi setiap orang yang diwajibkan solat, apabila tiba waktunya (untuk dilaksanakan). Dalam sunnah, terdapat sabda Nabi ﷺ: "Allah tidak menerima solat tanpa bersuci, dan tidak menerima sedekah daripada harta rampasan yang diambil secara curang," serta sabda baginda: "Allah tidak menerima solat seseorang yang berhadas sehingga dia berwuduk." Kedua-dua hadis ini adalah sahih menurut para ahli hadis terkemuka. Dalilnya dari ijmak ialah ketiadaan riwayat daripada mana-mana orang Islam yang mempertikaikan kewajipannya. Sekiranya terdapat perselisihan, ia pasti akan diriwayatkan kerana tuntutan amalan.

In the Qur’an it is in the words of the Exalted: “O ye who believe, when ye rise up for prayer, wash your faces and your hands up to the elbows, arid lightly rub your heads and (wash) your feet up to the ankles”.26 27 28 29 The Muslim jurists agreed that obedience to this communication is obligatory for each person on whom prayer is obligatory, when it is time for it(s) (performance). In the sunna, it is in the words of the Prophet (God’s peace and blessings be upon him) “Allah neither accepts prayers without purity nor charity out of purloined wealth [of spoils]”, and in his saying, “Allah does not accept prayers from one who has acquired hadath till he performs ablution”. These two traditions are authentic according to the leading traditionists. Its evidence in ijmdS is based on the absence of a transmission from any of the Muslims disputing its obligation. Had there been a dispute, it would necessarily have been transmitted because of the demands of practice.