In the incident involving the daughter of Rav Chisda, Rava stated "and I last".
The Maharsha comments that Rava certainly didn't curse Rami bar Chama that he should pass away before him, rather Rava meant that Rami bar Chama will divorce her, and he, Rava, will marry her.
This presupposes that Rava was not a Kohen.
Indeed, Rashi to Rosh Hashana 18a D"H Abaye and Tosfot ibid D"H Rabah (and in other locations) state that Rava was not a Kohen.
However, Rashi to Chulin 133a D"H Zachi Li and the Meiri ibid D"H Meachar state that Rava was indeed a Kohen. (The contradiction in Rashi's statements is noted by the Gilyon Hashas in Chulin ibid.)
The difficulty:
How do those that hold that Rava was a Kohen interpret Rava's statement. It is inconceiveable that Rava would Chas ve'Shalom curse Rami bar Chama.
Sincerely,
Mordechai Schwimmer
Mordechai Schwimmer, Brooklyn, USA
It seems that the consensus among the Mefarshim is that Rava was not a Kohen (see Seder ha'Doros, "Resh") and that actually it was Rabah who was a descendent of Eli.
As for those who hold that Rava was a Kohen, Rabbi Kornfeld suggests that Rava was basing himself on the principle that only a Nevu'ah for good must be fulfilled, and therefore he wished to nullify the part of the Nevu'ah which would suggest otherwise.
It was also suggested that Rava did not accept what Bas Rav Chisda said as Nevu'ah (as per the Girsa of the Bach ("v'Chein Hayah") that it was not previously accepted as Nevu'ah) and Rava's declaration of "v'Ani Basra" was not that he should be second, but rather that he should be last , meaning that in any event Rami bar Chama should not follow him, which would suggest death or divorce.
D. Zupnik