Here it says that they buried them under the Alah. In Shmuel I, 31:13 it says under the Eshel!
Radak: Eshel is a general word that includes all trees. 1 The same applies to "va'Yita Eshel" (Bereishis 21:33). In Divrei ha'Yamim, it explains that the tree was an Alah (oak).
Malbim: It is a type of tree.
Why did Anshei Yavesh Gil'ad exert themselves for Sha'ul and his sons more than other Yisraelim did?
'Rashi', Radak (10), from Pirkei d'R. Eliezer 17: Sha'ul saved them when Nachash threatened them.
Why did they fast for seven days?
Radak): This corresponds to the seven days that Nachash gave them when he threatened them, and Sha'ul saved them. 'Rashi' #1- also then they fasted, hoping for salvation.
'Rashi' #2: They conducted Aveilus 1 , for they were their relatives. After Pilegesh b'Giv'ah, the 600 men of Binyamin were left without wives; 400 took girls of Yavesh Gil'ad 2 , and the rest took from dancing girls of Shilo.
Pirkei d'R. Eliezer 17: They fasted, cried and eulogized, to bestow Chesed to Sha'ul and his sons. (An Avel need not fast! And surely the entire city was not related to them! Perhaps all considered themselves Safek relatives; the only survivors of the city were virgins, who (especially very young girls) often do not know all their relatives. This is like the opinion that Pilegesh b'Giv'ah occurred at the end of the Shofetim (refer to Shofetim 18:1:2:1-2), but unlike the opinion that Sha'ul married one of the dancing girls (refer to Shmuel I, 20:30:1:2). - PF)
After Yisrael killed all the males and the married women, for Yavesh Gil'ad did not come to fight against Binyamin (Shofetim 21:11-12).
