It was narrated from Abu Hurairah and from `Ubaidullah bin Abi Rafi`, from his father, from `Ali (رضي الله عنه), that they (Abu Hurairah and ‘Ali) said:
The Prophet (ﷺ) said: `Were it not that it would be too difficult for the ummah, I would have commanded them to use the siwak at the time of every prayer.”