Musnad al-Imam ash-Shafi'i (2 volumes)

The Musnad ach-Shafi'i is a collection of hadith used in the Madhhab Shafii as argument. It is classified by chapter of Fiqh.

So this work is actually a collective work of the first imams of the Madhhab containing the hadiths reported and which appear in al-Umm and al-Mabsut, both of Imam Shafii.
So it does not figure as one of the works of the Imam as ibn Hajar al-'Asqalani explains. Nevertheless, it remains a known and used collection.

Very beautiful verified and authenticated edition, with the degree of authenticity of the hadiths in annotations, and the harakats partly on the hadiths, and with several search indexes.