Sotah 11b: In Egypt women would go to their husbands in the field, wash and anoint them, give them to eat and drink, and cohabit with them in ridges between the fields. In this merit, Yisrael merited the spoils of Mitzrayim - "dove's wings covered with silver, and its pinions with fine gold."

Rashi: So He tells the kings of the nations - when you lied amidst your borders and indulged in pleasures, My congregation (Yisrael, my dove)

Shabbos 49a: Keneses Yisrael is compared to a dove. Just like a dove's wings protect it [from cold, and it uses them to fight off attackers], Yisrael's Mitzvos protect them.

Refer to 68:14:1:1,3.

Rashi: The dove's (Yisrael's) feathers are covered with desire for Torah and Mitzvos. Its wings are covered with fine gold from Chavilah and Kush. The gold is not Yarok (yellow) and not red, therefore it is called Yerakrak; so explains Dunash.

Radak #1: [If you went dark due to the enemy's oppression. you will be white] like dove's wings, as if you are covered with silver. A dove's wings have a feather that shines like gold; the gold is called Charutz - "v'Charutz k'Tit Chutzos" (Zecharim 9:3). Yerakrak (yellow) gold is best. The adjective comes before the noun, unlike normal grammar. We find like this - "Avtit" (Chabakuk 2:6), in place of Tit Av, "Kol Rabim Amim" (below, 89:51) in place of Kol Amim Rabim.

Radak #2: This hints to the gold and silver that Yisrael took from Ashur's camp (after the angel killed them).

Malbim: Yisrael are like a dove among beasts and vicious birds of prey (the nations). Hashem tells the nations, know that the dove is covered with silver, and its wings are covered with fine yellow gold - it is beautiful and strong. It is as if it is covered with metal, so one cannot bite it. Even though a dove is weak, it fights with its wings against birds of prey that come to plunder its nest.