1)
Why did Yo'av send to Teko'a?
1.
Rashi citing Menachos 85b: Olive oil is readily available there, therefore Chachmah is found there. Radak - it is the best place in Eretz Yisrael for olive oil. It was in Asher's portion - "v'Tovel ba'Shemen Raglo" (Devarim 33:24). Oil flows like a river there.
2.
Malbim citing Mahari: Teko'a is on a mountain - "uvi'Sko'a Tik'u Shofar" (Yirmeyah 6:1). Mountain dwellers are generally strong, wise and courageous.
2)
Why did he say "Na"?
1.
Malbim: This shows immediacy. Immediately she should begin to mourn, cry, eulogize, wear mourners' clothes and not anoint, so she will be like one who has been mourning many days over a Mes.
