I hate, I despise your feast days, and I will not smell in your solemn assemblies. So has Persius; see Sat. 2 v. 71-75: -
"Quin damus id Superis, de magna quod dare lanae," etc.
The two or three last pages of Plato's Euthyphro contain the same idea. Sacrifices and prayers are not profitable to the offerer, nor acceptable to the gods, unless accompanied with an upright life.
The fat of fed beasts, etc. - The fat and the blood are particularly mentioned, because these were in all sacrifices set apart to God. The fat was always burnt upon the altar, and the blood was partly sprinkled, differently on different occasions, and partly poured out at the bottom of the altar. See Leviticus 4.
Amos 5:21I hate, I despise your feast days - I abominate those sacrificial festivals where there is no piety, and I despise them because they pretend to be what they are not. This may refer to the three annual festivals which were still observed in a certain way among the Israelites.