Indeed, your Rabb knows well (from their being) who has gone astray from His way. And He knows well who has attained the reality (as He is present within their being)!
Al-muntakhab fi tafsir al-Qur'an al-Karim
Allah your Creator, is He Who knows best those who have wandered from the path of rectitude, and those who have been guided by the spirit of truth into all truth