Why didn't they offer the same day?
'Rashi': After David said all his words, there was not time left in the day. After they left the meeting, they went to buy animals for Korbanos.
Why did they offer the same number of bulls, rams and sheep?
'Rashi': This is like "Eilim Chamishah Atudim Chamishah..." (Bamidbar 7:17) - the same amount of each 1 .
There, each Nasi offered for Shelamim two bulls, and five each of rams, goats and lambs - four species in all, and fewer bulls. It is better to say that they offered Olos like the Olah of each Nasi (one bull, ram and lamb) - the same three species as here, and the same amount of each! Perhaps 'Rashi' wrote only 'like the Nesi'im', and a scribe mistakenly wrote in place of this "Eilim Chamishah..." (PF)
Initially, it said Zevachim and Olos. Why does it say "u'Zevachim la'Rov" at the end?
'Rashi': Verses that mention and later discuss two or three matters, they [often] leave the first matter for the end, and discuss the last immediately. Similarly, it says "Lavan came in Yakov's tent... and he came [from Leah's tent] to Rachel's tent" (Bereishis 31:33). After saying that he did not find [his Terafim] in the other tents, it explains that he went from Leah's tent to Rachel's tent.
'Rashi' (22): It is in order to put "u'Zevachim la'Rov" next to eating (in verse 22).
