Ат-Тавба 9:108

Never stand, [never] perform prayer, there: and so he sent a group of men to destroy and burn it, and in its place they left a refuse pit where decaying cadavers would be dumped. A mosque which was founded, one whose foundations were built, upon piety from the first day, constructed the day you arrived in Medina (dār al-hijra) — this was the mosque of Qubā’, as mentioned in Bukhārī — is worthier, than that [other one], for you to stand, to perform prayer, therein; in it are men, namely, the Ansār, who love to purify themselves; and God loves those who purify themselves (muttahhirīn: the original tā’ [of mutatahhirūn] has been assimilated with the tā’) that is, He will reward them. Ibn Khuzayma reported in his Sahīh [by way of an isnād] from [‘Uwaym] b. Sā‘ida that: ‘The Prophet (s) came to them at the mosque of Qubā’ and said, “God, exalted be He, has praised handsomely the way you purify yourselves in the story about your mosque, so what is this purification which you perform?” They said, “By God, O Messenger of God, all that we know is that we used to have Jews in our vicinity and they used to wash their behinds after defecation, and so we began to wash in the way they did”’. According to one hadīth reported by al-Bazzār [they said]: ‘We use stones [to scrape off remnants] and follow this with water’; to which he [the Prophet] said, ‘That is the way [for proper purification]. Let this be your way’.