There are at least three possible explanations of the Pasuk “Zeh Keili VeAnveihu” (Shemot 15:2). Onkelos says it refers to building Hashem a dwelling or abode, meaning the Beit HaMikdash. The Gemara (Shabbat 133b) understands it to refer to the concept of Hiddur Mitzvah, doing Mitzvot in the most beautiful way (stemming from the word Noi). Alternatively, Bnei Yisrael promise to sing about about Hashem’s greatness.
On the surface, these different comments seem unrelated. There are, however, two different ways to connect them. Rav Mordechai Gifter postulates that these are all crucial steps in the proper way to serve Hashem. After Kriat Yam Suf, Bnei Yisrael had divine revelation on an unprecedented scale. It was so great that Chazal say a maidservant at Kriat Yam Suf had more revelation than later Neviim. This degree of Divine revelation leads to the affected being overcome with love for Hashem, causing him to yearn to demonstrate his love in every possible way. Anyone who experiences this strives to beautify all of the Mitzvot, whether physical or spiritual.
Alternatively, Rav Moshe Feinstein explains that part of human nature is to beautify all of the important things in life, such as one’s home, clothing and food. People feel pride when they accomplish these tasks. If someone considers Torah and Mitzvot essential needs of life, he will want to make them as beautiful as possible, lest it seem as though they are a burden. Just as one would be proud of his material possessions, he should be proud of his Mitzvot. Despite the model of humility required by Judaism, we are allowed to take pride in the Mitzvot we perform, as it says in Yirmayahu, “Of this the boaster may boast: Of wisdom and knowledge of Me” (9:23). If someone does not take pride in his Mitzvot, it is due to his lack of consideration of the importance of them. We should be proud of the Mitzvot we do. This reveals how all explanations branch out from Onkelos’s explanation. Just as we take great pride in the magnificence of our physical homes, so too we should take great pride in our spiritual home, the Beit Hamikdash, and glorify it. By extension, we should apply this concept to Torah and Mitzvot, and praise Hashem for giving them to us.