What is the authenticity of the Hadith which mentions that reciting a specific supplication morning and evening grants the Muslim a covenant with God, guaranteeing him entry into Paradise on the Day of Resurrection?

The gist of the Fatwa: The aforementioned Hadith was narrated by Imam Ahmad in his Musnad from Abdullah ibn Mas'ud, and it states that whoever recites a specific supplication is guaranteed Paradise by Allah. It was authenticated by Al-Hakim and Al-Dhahabi. However, Al-Haythami deemed it weak due to an interruption in the chain of narration between 'Awf ibn Abdullah and Ibn Mas'ud. Furthermore, the addition "And when he says that, Allah stamps a seal upon it" has not been found as a Marfu' (attributed to the Prophet) or Mawquf (attributed to a Companion) narration.