Quoting Commentary for Song of Songs 8:12

In its stating Bereishit, it also wants [to teach], by way of the [Sages], may they be blessed, saying (Zohar Chadash, Bereishit 2) that a thousand hidden worlds did God create; and they, of blessed memory, called them (Edra Zuta, Ha'azinu 288a) 'worlds of embarrassment;' and they are hinted to in the verse (Song of Songs 8:12), "there is a thousand to you, Shlomo." And from here, the verse began with bet, since alef had already acquired its place, since with it were created a thousand (elef which is spelled that same way as alef) worlds, according to its name, alef. And He started with bet to create this world, given that [its numerical value] is also the sum of the creation which is two, heavens and earth. And also for this reason, it did not state, "At first," since you would understand that this is the [absolute] beginning, and that is not the case; since He already created the 'beautiful worlds,' but regarding this detail of the heavens and the earth, it is stating its beginning.

“And the earth” – this word is an unusual [form], since it appears with a kamatz in the alef when [preceded by] the hey [i.e., the definite article] in all places. It is not like “The thousand (ha’elef) for you, Shlomo” Song of Songs 8:12, or “and this stone ha’even” Genesis 28:22.

And gather you from all of the nations: After the main exile returns from the nations, the Lord will return to gather the small pockets among the nations where the Lord scattered you. Likewise did Ramban write 1 in his commentary on Song of Songs (8:12), "you may have the thousand, O Solomon" - that at first, there will be a partial gathering of the exiles with the permission of the governments. And afterwards, the Lord will bring back His hand a second time, as it is written, "and He will return and gather you."