1. Kem Na Mazda is a powerful prayer to invoke Ahura Mazda’s protection. It is a prayer which can be recited separately by itself. It is next only to the Yatha Ahu vairyo in efficacy, for protection. Almost one-third of it is from the Gathas, and the rest is taken from the Vendidad.
2. In the Kem na Mazda prayer, different types of protections are mentioned. First is the protection with divine energy, then with divine wisdom and divine intelligence. Thereafter protection from ignorance through the help of a teacher, and finally protection from Nasu, that is physical contagion and impurities. Protection is sought through Armaiti (Aspandad Ameshaspand), that is, mother earth, who absorbs all the organic impurities, and changes them to goodness. Just by reciting the Kem na Mazda prayer, a person is assured of protection from unseen evils.
3. Kem na Mazda is recited right at the beginning of the Kasti ritual. Only after reciting it can one untie the Kasti. Zoroastrians have the Sadra and Kasti on the body 24 hours of the day, which protects them from seen and unseen evils. However, while performing the Kasti ritual, when one has to untie the Kasti and remove it from the waist for a few minutes. It is at that time that the prayer of Kem na Mazda gives protection, when one is without the Kasti.
4. In present times, it is very beneficial to recite the Kem na Mazda before going to sleep and before going for bath, swimming, or whenever one has to be without the Sadra Kasti.
5. Kem Na Mazda is incorporated in larger prayers like the Sarosh Baj and Hoshbam. It is recited in the Baj taken before bath, the Bāj of Paydast, as well as in Bareshnum, Sackar, Geh-sarna and Vendidad rituals.
Since it is a potent protection against the deadliest Nasu, emanating from the corpse, even the Khandhias and Nase-salars recite it while handling the corpse and placing it in the Dakhma.
6. While reciting the words ‘Vohu Sarosho jantu Mananghā’ in the Kem na Mazda, the person is calling Sarosh Yazad and Bahman Ameshaspand for help.
7. The last line of this prayer, ‘Nemaschā yā Ārmaitish izāchā’ is from the Spentomad Gatha. It means “Homage unto Armaiti, who is giver of prosperity.” Here, by invoking Armaiti, that is Spandarmad Ameshaspand, we are thanking mother earth for her tolerance and beneficence on account of which we are able to live happily on this earth. That is why we bow down and pay homage to the earth while saying this line. Some people recite this line thrice, but it is not necessary to do so.