D'var Torah: The revelation of the Shechinah (the Divine Presence) that dwelt in the Mishkan was the same revelation of the Shechinah that Klal Yisrael experienced at Mount Sinai. In this light, HaShem spoke to Moshe in the Mishkan with the same awesome voice and revealed the same glowing holiness that Moshe perceived at Mount Sinai. What was the merit of Klal Yisrael that awakened this supreme holiness and closeness to HaShem in the Mishkan? The verse states (Shemos 25:2), "Speak to the Children of Israel, and have them bring an offering for me, from every person whose heart inspires him, you shall take My offering." They voluntarily brought their offerings of gold and silver to build the Mishkan, as per the verse, "from every person whose heart inspires him..." Their heartfelt inspiration to bring their offerings to build the Mishkan, awakened the glory of the Shechinah of Mount Sinai to dwell in the Mishkan.
Moral: Klal Yisrael donated the materials to build the Mishkan not out of obligation, rather the love of HaShem in their hearts inspired them to bring their offerings. Since they deeply aspired to come close to HaShem, correspondingly, HaShem came intensely close to them.
Application: Imagine that you are standing with Klal Yisrael in the desert. Hear Moshe Rabenu ask the nation to voluntarily donate materials to build the Mishkan. Sense the heartfelt resolve of Klal Yisrael to bring the gold and silver in order to come close to HaShem. Envision yourself and thousands of others joyously bringing the required materials to Moshe Rabenu. Experience the awesome holiness of Mount Sinai that HaShem revealed in the Mishkan.
(Based on the commentary of the Ramban to the Chumash)