It was narrated from Abu Hurairah that the Messenger of Allah (ﷺ) said:"Were it not that I would impose too much difficulty on my Ummah, I would have commanded them to delay 'Isha' and to use the Siwak for every prayer
Hadith No. 534
Sunan an Nasai
Gradings:
Abu Ghuddah:
Sahih
Al-Albani:
Daif
Zubair Ali Zai:
Sahih Muslim