1)
Why does it say that Yo'av was over the army?
1.
'Rashi': Because David refrained from going out to war, he placed Yo'av over the army to fight all his wars. Do not infer that if David refrained from war, and sat and judged, there were no more wars.
2)
What is the meaning of "Mazkir"?
1.
'Rashi', Rashi (Shmuel II, 8:16): He mentions which judgment came first, to rule about it first.
2.
Radak (Shmuel II, 8:16, citing Targum Yonasan): He was appointed over the chronicles. 'Rashi' - We find like this "Lehavi Es Sefer ha'Zichronos Divrei ha'Yamim" (Esther 6:1).
