Sunan an Nasai
5
Sahih+2

Abdur-Rahman bin Abu 'Atiq said:"My father told me: 'I heard 'Aishah say, (narrating) from the Prophet (ﷺ): "Siwak is a means of purification for the mouth and is pleasing to the Lord

SahihAbu Ghuddah
SahihAl-Albani