What is "Ad she'Yafu'ach ha'Yom"?
Rashi: It is until [heat of] the sun spreads. Ha'Yom is the sun, like "l'Ru'ach ha'Yom" (Bereishis 3:8) and "Hinei ha'Yom Ba Bo'er ka'Tanur" (Mal'achi 3:19). After this time, I will go to Har ha'Moriyah [and dwell] in Beis Olamim. I.e. from when they sinned in front of Me to profane My Kodshim and despise My Minchah in the days of Chofni and Pinchas, I will remove My Shechinah from you and abandon this Mishkan (Shilo), and chose for Myself in Har ha'Moriyah, in the Beis ha'Mikdash. There, "Kulach Yafah Rayasi u'Mum Ein Bach" (7) - there I will desire all your Korbanos.
Seforno: This will be until the light of afternoon, in the days of David, who guided Yisrael in investigation and deed - "v'Nasvah Es Aron Elokeinu Elenu Ki Lo Derashnuhu bi'Ymei Sha'ul" (Divrei ha'Yamim I, 13:3).
Malbim (Melitzah): This connection of the Kadosh Lover with His beloved] will be until the Nefesh is not prepared to cling to Nevu'ah. Even so, the Shechinah will not depart even after Bnos Tziyon (physical powers) return to their strength. This is because the Shechinah is fixed via the Mikdash and its Korbanos, not via intellect, understanding and Nevu'ah alone, like until now. That cannot persist on a fixed basis, for physicality blocks having Divine visions constantly. Now, the choicest food will be elevated via Avodas ha'Mikdash to be food for Nefesh Chiyunis, and what is even choicer will be for the intellectual Nefesh.
Malbim (Mashal): Our connection will be until the day gets hot and the shadows flee - then Bnos Tziyon will return.
What is the significance of the shadows fleeing?
Rashi: It is the hottest part of the day. I will save you, and you will be pleasant to Me.
Seforno: [David] removed from the land the abominations (idolatry) that blocked the light of life.
Malbim (Mashal): Refer to 4:6:1:4.
What is "Har ha'Mor [v'Giv'as ha'Levonah]"?
Rashi: It is Har ha'Moriyah. Seforno - it is in the granary of Aravna.
Malbim (Melitzah): We explained (1:13, 3:6) that Mor depicts the choicest parts of Nefesh ha'Chiyunis. Myrrh is musk - aromatic blood in an Indian Chayah. This depicts the scented. Levonah is the choicest vegetative scent. I.e. [the Nefesh] will willingly accept the parts of the spiritual fires that rise from offering animals and throwing their blood on the Mizbe'ach (Har ha'Mor) and the clearest parts of Menachos and Nesachim - the choicest of vegetation. It says Giv'as ha'Levonah, for vegetative is less than animate (like a hill is smaller than a mountain). Even so, Nefesh ha'Tzomachas supports Nefesh ha'Chai, just like a mountain is supported on hills below it. Via this, He will not separate from His beloved even when Yafu'ach ha'Yom. He will receive "Re'ach Nicho'ach" (Bamidbar 28:6) even from Nefashos dependent on physicality.
Malbim (Mashal): Even when Bnos Tziyon will return, I will not go far, only to Har ha'Mor temporarily.
What is "Giv'as ha'Levonah"?
Seforno: It is Har ha'Bayis, in the days of Shlomo.
Malbim (Melitzah): Refer to 4:6:3:2.