faqih-66Vol. 1, p. 33
إِذَا دَخَلَ الْوَقْتُ وَجَبَ الطَّهُورُ وَ الصَّلَاةُ[3] وَ لَا صَلَاةَ إِلَّا بِطَهُورٍ
Hadith.67 - Imam Muhammad ibn Ali Al-Baqir (as) said: "When the time for prayer enters, purification (ablution) and the prayer become obligatory, and there is no prayer without purification."