(اللَّهُ لا إِلَهَ إِلا هُوَ الْحَيُّ الْقَيُّومُ لا تَأْخُذُهُ سِنَةٌ وَلاَ نَوْمٌ...)

It is also from the Sunnah to recite āyah al-Kursī after each prayer: [Sūrah al-Baqarah, 2:255]

Reference: It is also from the Sunnah to recite āyah al-Kursī after each prayer: [Sūrah al-Baqarah, 2:255] Al-Nasāʾī in _ʿAmal al-Yawm wa al-Laylah_ (100) and Ibn Sinnī . Al-Albānī authenticated it in _Ṣaḥīḥ al-Jāmiʿ_ (#6464, 5/339) and _Silsilah al-Ahādīth al-Ṣaḥīḥah_ (#972, 2/697).