Why did he mention a wall, doors and bolts?
Gra: If one of these three is omitted, it is not fortified.
Why did he say "the land is still in front of us"?
'Rashi': Now that the kingdom is secure in front of us, we should build these cities for refuge, if needed.
Malbim: Our current serenity is a miracle from Hashgachas Hashem. One does not always merit a miracle! At this time, we should seek natural means to strengthen ourselves.
Why did he say "Ki Darashnu?"?
'Rashi': Because we sought Hashem, He gave to us respite.
Why is "Darashnu" repeated?
'Rashi' (12:7): It is because "Es Hashem Elokeinu" interrupts in the middle. Also Nichna'u is repeated above (12:7), and it says "v'Hayah Ki Selech Imanu v'Hayah ha'Tov?" (Bamidbar 10:32).
Gra: The first Drishah (seeking) is for Hashem, like it says in verse 3. The latter is for Torah and Mitzvos.
Malbim: There is no limit to seeking Hashem. There are many levels in Avodas Hashem. Since we sought more, He gave to us more serenity.
Why did they succeed?
'Rashi': It is because they sought Hashem. This is like "when Hashem saw that they were humbled?" (12:7).
