Hadhrat Moulana Zakariyya Kaandh’lewi رحمه الله commenting on this verse below mentions,
Surah 5 – Al-Maaida – Ayah 3
أَعـوذُ بِاللهِ مِنَ الشَّيْـطانِ الرَّجيـم
بِسْمِ اللّٰهِ الرَّحْمٰنِ الرَّحِيْمِ
ؕ اَلۡيَوۡمَ اَكۡمَلۡتُ لَـكُمۡ دِيۡنَكُمۡ وَاَ تۡمَمۡتُ عَلَيۡكُمۡ نِعۡمَتِىۡ وَرَضِيۡتُ لَـكُمُ الۡاِسۡلَامَ دِيۡنًا ؕ
Today, I have perfected your religion for you, and have completed My blessing upon you, and chosen Is-lam as Din for you.
One of the great virtues of Hajj is that this verse announcing the completion of the Din was revealed at the time of Hajj.
Imaam Ghazaali رحمه الله writes in his Ihyaa: “Hajj is one of the fundamental principles of Islaam. Upon it the foundation of Islaam became complete and the Dien was completed. It was at the time of Hajj that this Aayah was revealed.”
Virtues Of Hajj