The Messenger of Allah ﷺ commanded me to recite Mu'awwidhatan (the last two surahs of the Qur'an) after every prayer. (Using translation from Abū Dāʾūd 1523)
أَنَّهُ قَالَ أَمَرَنِي رَسُولُ اللهِ ﷺ أَنْ أَقْرَأَ بِالْمُعَوِّذَاتِ فِي دُبُرِ كُلِّ صَلَاةٍ