Who was Yehoyada?
'Rashi', Radak, Malbim: He was Benayahu's father 1 . 'Rashi' ? Yehoyada in the days of Yo'ash (Melachim II, 12:3) was the son of Benayahu ben Yehoyada 2 .
Many verses say that Benayahu's father was Yehoyada, e.g. Shmuel II, 8:18. However, Benayahu also had a son Yehoyada who advised David (below, 27:34)! (PF)
Yehoyada lived at least 23 years into the reign of Yo'ash (Melachim II, 12:8), 200 years after David became king [in Chevron]! Yehoyada lived 130 years (Divrei ha'Yamim II, 24:15). 'Rashi' must say that Benayahu fathered him 70 years after David became king, 30 years after David died. Below (27:34) it says that Yehoyada ben Benayahu was in the days of David; 'Rashi' says that he advised him! Perhaps later Benayahu fathered another son and called him Yehoyada, e.g. if the first Yehoyada had died. (PF)
Why is he called "ha'Nagid l'Aharon"?
'Rashi': He takes [them] out and brings [them] in. (I.e. he was the Sar and leader, like Malbim says. ? PF)
Radak: He is the leader of Aharon's seed, i.e. the Kohen Gadol 1 .
Even though he is not listed above (5:30-41) among the Kohanim Gedolim from Pinchas until Churban ha'Bayis, also Yehoyada the mentor of Yo'ash (Melachim II, 12:3) is not listed there! Some say that the latter is listed there under a different name, or he is not listed because his son did not succeed him once he died (refer to 5:36:3:1-2). We can answer similarly for this Yehoyada. (PF)
Were all 3,700 Kohanim?
'Rashi': Yes.
