Shishupalavadha parva is the twenty seventh upa parva included in the second maha parva, named as sabha parva, in the epic Mahabharata. Various compilations of this epic are numbered differently and this one upa parva may be numbered in a different fashion in them. Vyshampayana had narrated the historical events to Janamejaya, on his queries:
What did Yudhishtira do when the king of Chedi, Shishupala had revolted in the Rajasuya, gathering with his supported kings?
Yudhishtira had consulted Bhishma for further actions needed when the king of Chedi, Shishupala had revolted in the Rajasuya gathering with his supported kings.

What was told by Bhishma?
Bhishma was a senior ruler, aged and experienced. Bhishma told Yudhishtira not to be worried about Shishupala since Krishna had rightfully deserved the first honor.