It is said that when Lord Shiva fought a demon called Andhaka, a drop of perspiration of Lord Shiva fell on the ground and turned into Vastu Purusha. Vastu Purusha was very hungry and he devoured everything that was there. Then, Lord Brahma makes 45 deities to hold the Vastu Purusha face down on the ground and blesses him saying that he shall be the deity of all the plots. Lord Brahma also said that people shall make offerings to the Vastu Purusha and he in return shall protect the inmates of the house.
There are three positions of Vastu Purusha and there are:
- Nitya Vastu: In this his gaze changes every three hours.
- Chara Vastu: According to this the Vastu Purusha gazes at a different direction at different months.
- Sthira Vastu: This is most important and the most well known. As per this the position of the Vastu Purusha would be as in Fig1 and the positions of the deities holding him would be as in Fig 2.
In Fig 1, you will find that his feet is in the southwest, left arm in Northwest, right arm in Southeast and head in the Northeast.
The classical works on Vastu include Mayamata, Brihat Samhita and Manasara. Matsyapurana states that there were eighteen saints who were proficient in Vastu. They were Bhrigu, Atri, Vasishta, Viswakarma, Maya, Narada, Nagnajitha, Visalaaksha, Purandhara, Brahma, Kumara, Nandisa, Saunaka, Gaarga, Vaasudeva, Anirudha, Sukra and Brihaspati.