How sound is the Hadith: "Whoever brings joy to a Muslim, Allah creates from that joy an angel that worships Allah, and for the one who brought the joy is the reward of its worship, and when he dies, it comes to him in his grave and comforts him and says to him: 'I am the joy that you brought to so-and-so'"?

The aforementioned hadith was narrated by Ibn Abi Al-Dunya with the wording: "There is no believer who brings joy..." and it is a very weak hadith, as stated by Al-Albani. Nevertheless, bringing joy to a believer is among the best deeds and greatest acts of devotion to Allah, as stated in another hadith: "Among the best deeds is bringing joy to a believer..." and it is an authentic hadith.