All those who were generous of heart brought earrings, nose rings, finger rings, and bracelets--gold objects of all kinds--as well as all those donated a wave offering of gold to G-d.
Ibn Ezra, Shemot 35:22
Allegorically, this list of items that the women donated alludes to the four aspects of proper
child-rearing and Jewish education, the purpose of which is to raise children who will transform the world into G-d's home:
Earrings: listening to the Torah's instructions in all aspects of educating children. Also, listening carefully to children's conversations with their peers, for children learn how to talk from their elder's example; if something is amiss in how they speak, it means something is amiss in how their role-models speak.
Nose rings: Develop a keen sense of "smell" to determine if children's friendships with other children are beneficial.
Finger rings: Pointing children to the proper path, by gently guiding them to adhere to the Torah's teachings and not to follow harmful paths.
Bracelets: Being strong-armed--for even if children are well-behaved, it is necessary to be firm with them in order to foster their enthusiasm for their studies.
--From Kehot's
Chumash Shemot