Shiva Sutras by Jaideva Singh, Section II(comprises of 10 Sutras) greatly deals with mantras, mudras and science, etymology behind it.
The very first Sutras says:
चित्तम् in this context means that by which the Highest
Reality is cognised.
मन्त्रः a formula consisting of a word or a set of words addressed to a deity.
I was able to find more details about Agnihotra Homa which helps in purification of surroundings, cleansing of air and elimination of bacteria, viruses etc. As one answer says there are lot of incorrect videos and blogs describing Agnihotra , so I went looking for an answer in scriptures and found some information in Asvalayana Grihya Sutra
From Adhyaya 1 , ...
उों नमो भगवते श्री-उड्डामरेश्वराय अमुकं उच्चाटय २
विद्वेषय २ स्वाहा ।
The IAST transliteration of above mantra taken from sanscript:
uoṃ namo bhagavate śrī-uḍḍāmareśvarāya amukaṃ uccāṭaya 2
vidveṣaya 2 svāhā ।
Literal meaning of "Namah Shivaya" is "adoration to Shiva". "Namah Shivaya" also represents panchabhutas(5 elements). It is well explained by Bodhinatha Veylanswami ji in his book Path to Siva. I'll quote that part here:
Namaḥ Śivāya is the most famous and holy of Saivite mantras, chanted daily by millions of devotees. Namaḥ Śivāya means “adoration to ...
Please see below from Kamika Agama, Purva Pada (Verses 1-3, Chapter 2). Agamas are shrutis (just like vedas) revealed by Lord Shiva himself. So the point of questioning them does not arise.
The first stanza says there is no action is to be conducted without a mantra - be it tilling the land or regular worship.
Second stanza says there "manana" is the ...