Rabi'ah (may Allah have mercy on him), explaining the hadith of the Prophet (peace and blessings be upon him), "There is no ablution for the one who has not mentioned the name of Allah," says that it refers to the person who performs ablution or a ritual bath but does not intend, in the ablution, (ablution for) the prayer, nor, in the ritual bath, purification.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 184