How is the love of its rocks and earth expressed?
Kesuvos 112b: R. Aba used to kiss the rocks of Ako. R. Chanina would level places where one might stumble (lest people disparage the roads). R. Ami and R. Asi would go to a shady or sunny area, according to the weather (to prevent complaints). R. Chiya bar Gamda would roll in the earth - "Your servants love its stones and its earth." 1
Rashi citing a Midrash: When Yechanyah and those with him went out to Galus, they took with them rocks of Yerushalayim and its earth, to build a Beis ha'Keneses in Bavel.
Radak #1: When they are in Galus, they desire to kiss its rocks.
Radak #2: They want to establish its building.
Radak citing the Kuzari: Yerushalayim will be built when Yisrael have the ultimate desire for it - even for its rocks and earth.
Malbim: You will save them also due to the nation, that in their sins You destroyed Tziyon, for they already desired and appeased for their sins. Hashem poured His anger on the wood and rocks, and afterwards they desired its rocks, that their blood was spilled due to Yerushalayim's rocks and their Emunah.
Even though the verse discusses Tziyon, the Amora'im cherished the rocks and earth of all of Eretz Yisrael. (PF)
Why does it say "v'Afrah Yechonenu"?
Radak: A metaphor for this - a person has grace on something that he loves.
Malbim: They always mourn over it, and kiss its earth.
