(Told in bhaviShyottara purANam )
This vrata has been explained in the bhaviShyottara purANam. This vrata is told for the women without any caste creed restrictions to perform. This vrata could be started in the month of kArthikai (mid Nov to mid Dec). sUta paurANikar told the devout R^iShis assembled in the naimichAraNyam the greatness of this vrata.
Once pArvatI requested The Greatest Divine Lord, to tell about an austerity, which would bring the boons of prosperity, fertility and health and good being of husband and offsprings. The Lord replied that bhakteshvara vratam would be the answer for that. The Merciful Lord further explained that the lady who wishes to observe this vrata, in consensus with the husband, should start on the waxing moon period (shukla paxam) of the month kArthikai. Having completed the morning duties and bathed early in the morning, well dressed up in colorful dress, wearing turmeric and tilak, should make the Ishvara out of sandal, pArvatI out of turmeric and nandi out of sand. These forms would have to be hailed with the shiva mantras. After the sunset, either at home or at a temple, in a place washed with cow-dung and nicely decorated, install these divines. Since the devotee worships the Lord out of sincere devotion, this vrata is called bhakteshvara (Lord of devotion) vrata. Perform the meditation - installing rituals (Please refer to the link above - pUjA vidhAnam, for the same). It is suggested that a perforated plate (jalladai) be made out of bamboo and wound 33 times with golden fiber. This has to be placed over the sweet pancake (appam) made of lentil (dhal), ghee, sugar and flour on the ground. Over the bamboo plate a dosa has to be kept, over which sugar and ghee to be put. Make a lamp out of raw rice flour and light with ghee and place it over the dosa. Offer this to the Supreme gaurI bhakteshvara svAmi with love. Later donate off this offering praying for the well being of the donor and the receiver. Similarly in the next month (mArkazi - mid Dec - mid Jan) perform the pUja, this time with two such dosa and two flour lamps. The following month with three such things. Thus this vratam to be done till 33 times.
A king by name chandra pANdiyan was ruling from the city madhurai that stood on the bank of river kR^itamAla. He was a valorous and good-valued king and with his wife kumudvati. They had no offsprings. They did austerities staying in the forests, renouncing the sensual distractions, meditating on the Great yogi Lord shiva chanting the Holy Five Letters. The Gracious Lord shiva appeared with pArvatI and asked the king what boon he wanted. The king saluted the Lord and asked for a child. The Lord conveyed him that because of the bad deeds done in the previous births, he did not have an offspring. But the Lord Who does not withdraw blessing the devotees, provided him to choose a child either long living girl who would soon become a widow or a brilliant boy who would live for very short period. The king chose the second one. The Lord gave the boon. Soon the queen gave birth to a boy who was named Ishvara pANdiyan. The brilliant boy grew up learning well and was in the age well suited for marriage. There lived a king mitrasaha, a devotee of the Lord of matted hair, good in heart, who ruled from alahapuri. He and his wife got a girl kalyANi out of observing the bhakteshvara vratam. These two parents agreed for the marriage of their children and it happened in a ritualistic way. The brides parents along with the bride observed the bhakteshvara vratam before sending them off to the groom's place. At her husband's place, when the newly wedded girl was in the bed room, the death came to take away the life of her husband. The devoted girl was firm that she was living the life blessed by the boon of bhakteshvara vratam and pleaded to themR^ity~njaya to save her husbands life. The Lord came out as a serpent from the light nearby and bit the death. The death fell off. The Lord blessed the devotee kalyANi and gave her husband a long life. Later on the pleading of devas the God resurrected the death. Coming to know about this marvel the parents of the groom felt very happy and they also started observing this great vratam.