Torah Temimah citing Zevachim 116a #1: A nation (Nochrim) that only offers in the north (i.e. Olos) will be overturned, and will come [and dispossess them] a nation (Yisrael) that also offers also (Shelamim) in the south.

Zevachim 116a #2: It refers to the gathering of the exiles.

Rashi: Since your scent and beautiful dwellings are pleasant to Me, I command the north and south winds to blow in your garden to spread the nice scent afar.

Rashi according to the metaphor: The exiles gather, and all nations bring [Yisrael from their lands] to Yerushalayim for a gift. In the days when the Bayis is built, Yisrael gather there on Mo'adim and Regalim. Yisrael respond, let my Beloved come to His garden. If You are there, everything is there ¹ .

Seforno: [Chizkiyah] strove greatly to make Yisrael repent. "Couriers went with letters from the king