Riyad as-Salihin 15:49

'Abdullah bin Khubaib (May Allah be pleased with him) reported:

The Messenger of Allah (ﷺ) said to me, "Recite Surat Al-Ikhlas and Al- Mu'awwidhatain (Surat Al-Falaq and Surat An-Nas) three times at dawn and dusk. It will suffice you in all respects." [Abu Dawud and At-Tirmidhi] .