In numerous traditional reports, in the books of Shia as well as
Ahle Sunnat, it is mentioned that angels came to Ameerul Momineen
(a.s.); they greeted him and also sought forgiveness on behalf of his
supporters and Shia.
They still do the same and seek divine proximity through devotion to His Eminence and pride to remain in his service.
When Almighty Allah created the angels through His holy
effulgence, they learnt divine praise and glorification from the holy
spirits of Muhammad and Aale Muhammad (a.s.) that is why
Almighty Allah made their mastership (Wilayat) obligatory on His
proximate angels.
Behaarul Anwaar, vol. 39,p. 92
Isbaatul Wilayah (Part One) – Ayatullah AliNamazi Shahroodi (r.a.)