The words "new moons" are a metonym for the celebrations of the new moon. They are also a synecdoche for all regular celebrations. AT: "your celebrations of the new moon and your other regular feasts" (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-synecdoche]])
This compares how God feels about the people's celebrations to carrying a heavy object. AT: "they are a heavy load that I am tired of carrying" (See: [[rc://en/ta/man/translate/figs-metaphor]])
This is the reason that God will not listen to their prayers. The blood likely refers to violence that they have done against people. AT: "because it is like your hands are covered with the blood of those you have harmed" or "because you are guilty of violence" (See: [[rc://en/ta/man/translate/figs-metonymy]])