Vastoshpati - Lord of the dwelling
When we buy or rent a new house, it is not considered fit to dwell in until we do vastupuja. This rite is dedicated to the vastupurusha or spirit of the house who is none other than Bhagawan Rudra Himself.
A famous part of the Vedas is the sukta known as Shatarudriyam or Namaka. It is part of the Yajurveda and occurs in slightly different forms in the Shuklayajurveda (more prevalent amongst Brahmanas in the North parts of India) and Krshnayajurveda (more prevalent amongst Brahmanas of the South.) It is generally chanted in Shivalayas and on occasions when puja or abhisheka of Shiva Bhagawan is to be done. However it is a little known fact that it is actually asking Shiva Bhagawan to go away!
( Interesting follow discussion on this name:
Shri V. M. Sundaram notes:
None of the mantra-s in the rudra-prashna can be interpreted as asking shiva to go away. In fact the relevant portion of the mantra is namo vastupaaya ca. As per the bhaashhya, vaastu is gR^iha-nirmaaNaartha bhuumiH ; vaastupaH is tatpaalkaH - protector of the vaastu. It is the propitiation of rudra in his manifestation as vaastu-purushha that is meant while reciting the namakam, and not asking him to go away ! The other attendant rituals when a vaastu- shaanti is done are meant for driving away unwanted spirits like bhuuta-preta-pishaca-adi.
Sorry I don't know if the numbering is different in the Krishnayajurveda version but mantras 54-63 in the Shuklayajurveda version ask the various bands of Rudras that inhabit the earth to unstring their bows and depart
1000 yojanas away. Uvatacharya (Shayanachrya has not commented on this shruti or his commentary is not available.) agrees that this is the literal meaning and the purpose is to clear the ground for the
Agnichayana. This doesn't mean there can't be other meanings too, just that this is the meaning in the context of the Agnichayana.
> > Om Vastoshpataye namah
> I am eager to know where this naama occurs in this form. I do not
> find it in the shatarudriiya,or shiva sahasra naama.
It occurs in the Vedas as a surname of Rudra Bhagawan. According to Aptes dictionary, of Indra too but I don't know about that. In the Paraskara Grhyasutra (also belonging to Shuklayajurveda) it says offerings should be made to Rudra Vastoshpati during the Vastupuja.
The Vedic mantras are collected in the Samhita portion of each Vedic shakha. For instance the Shatarudriyam is the 16th adhyaya of the Vajasaneyi Samhita of the Shuklayajurveda. The next part of a shakha is
called Brahmana and deals with the use of mantras in yajnas of various sorts. The Shuklayajurveda has Shatapathabrahmana. The other two parts are aranyakas which deal with upasana and upanishads which as is well
known deal with Brahman. The distinction is not always clear cut. For instance in the Shuklayajurveda, Ishopanishad is the 40th adhyaya of the Vajasaneyi
Samhita, and Brhadaranyakopanishad is both the aranyaka and upanishad and forms the concluding chapters of the Shatapathabrahmana.
Anyway, this Shatapathabrahmana discusses the Shatarudriyam in the context of the Vedic yajna called Agnichayana. It says Shatarudriyam means Shantadaivatam. "That which placates the divinity" What is the meaning of this? Agnichayana is one of the most elaborate and powerful yajnas and involves building a vedi (altar) in the shape of a bird. Now the important thing about a yajna is to give of yourself. This is why it is translated as sacrifice. If you didn't give anything or you gave things that didn't belong to you, it wouldn't be much of a sacrifice would it? Ravana was even prepared to sacrifice his own heads to the Lord. That is the true spirit of yajna. In this Agnichayana, a vedi has to be built. But where? All the earth is the property of Shankara Bhagawan. So before the Agnichayana proper starts a preliminary Rudrayaga is to be done using the shatarudriya mantras to vacate the premises in peace so the yajna may continue fruitfully.
Even today in yajnas and pujas - vedokta, puranokta or tantrokta, when entering a new house, consecrating a new mandir, or erecting a lagna mandapa, we always remember that patch of lands true owner and only when He has given His permission for us to take temporary ownership can we go ahead and use it.
Om Vastoshpataye namah