Riyad as-Salihin

'Aishah (may Allah be pleased with her) reported: We used to prepare for the Messenger of Allah (ﷺ) a Miswak (tooth-stick) and the water for making Wudu'. Whenever Allah wished to awaken him from sleep at night, he (ﷺ) would brush his teeth with Miswak, make Wudu', and perform Salat.

[Muslim].