(24:5) How goodly are your tents Ya’akov, your dwellings Yisrael.

Why is the Jewish nation referred to first as Ya’akov and then as Yisrael? And why is the Beis Hamikdash referred to first as a tent and then as a dwelling?

The gemora teaches that when Yisrael do the will of Hashem they are called Yisrael, and when they do not obey Hashem’s will they are called Ya’akov.

And it says in the Midrash that when the Beis Hamikdash was standing it was called a tent, and when it was destroyed it was called a משכן, which means both a dwelling and a collateral, because the Beis Hamikdash was taken as collateral when it was destroyed for Yisrael’s sins, as Rashi writes in the beginning of parshas Pekudei.

The Midrash also teaches that as long as the Beis Hamikdash was standing the generation was called wicked, but when it was destroyed they became tzaddikim.

Thus Bilaam was saying to Yisrael: How goodly are your tents Ya’akov – when the Beis Hamikdash is called a tent, that is, when it is standing, it is good, but you are called Ya’akov because you are wicked. And how goodly are your dwellings Yisrael – when the Beis Hamikdash is destroyed and called by a name which means collateral, it is also good, because then you will be called Yisrael, because you obey Hashem’s will and thus be tzaddikim.