Awakening, Vishnu held Madhu Kaitabh and engaged them in a combat, which went on for five thousand years. The two demons then puffed up with pride, thinking themselves invincible. It was at this moment that the great goddess struck at the duo with her maya, making them vain enough to say to Lord Vishnu himself:
"We are pleased with your power and strength. Go ahead and ask for a boon."
Vishnu immediately seized the opportunity and asked for the boon that they be slain by him then and there. Indeed, one should always watch out for those moments of pride, which are the opportune instances for maya to delude us.
In another interpretation, Madhu is honeyed praise, while Kaitabh is sour criticism, both of which enter through our ears, but are two side of the same mayic coin and need to be discarded. In either of the interpretations, the two demons attack our intelligence, symbolized by Brahma who is the patron deity of intellect. The Bhagavad Gita says:
"When your intellect, though perplexed by what you have heard, shall stand immovable and steady, then shall you attain self-realization". (2.53)
However, we cannot win over the two demons of attachment/aversion or praise/criticism, relying solely on our own powers, like Lord Vishnu who was unable to defeat them even after many years of fierce battle. The only way to win over maya is to surrender ourselves to Mahamaya, the goddess who created it in the first place. The fact that the two demons asked to be killed in a dry spot is also loaded with spiritual symbolism. Both these pairs of traits can only be destroyed on the ground of Vairagya (disenchantment), which is the dry state of existence, devoid of all worldly rasa.
However, the state of the goddess symbolized by sleep is not her brightest manifestation. The Gita says:
"The pleasure arising from sleep is known as tamasic." (18.39)
Madhu Kaitabhameans "having a semblance to the quality of honeybees". What is the quality ofhoney bees? Well, they keep working hard to accumulate the sweet honey! They arenot intelligent enough to think about any higher things in life. Thus, MadhuKaitabha are an allegory to the quality within us which makes us work hard, likehoneybees, with a single-minded focus on accumulating material comforts. Likehoneybees accumulate honey, we accumulate material objects and spend whole lifeworking hard doing just that.
Vishnu is a personification of the sattwa guna of the Parama Purusha(Universal/Absolute Being). Within us, Vishnu is an allegory to the sattwa gunawithin us. Madhu Kaitabha were born from Vishnu's earwax when He was alseep. Theability to work hard like a bee is not really a terrible thing. This ability isessentially born from the sattwa guna within us, when it is in deep slumber(i.e. sattwa guna covered by taamasi shakti, i.e. sattwa guna that "manifests"in a taamasik way).
There are so many good people in this world, who just spend their entire livesin honest labor like the honeybees and accumulate things for themselves andothers around them. Their sattwa is in deep sleep and Madhu Kaitabha born fromthat asleep sattva are very much active.
The problem with this focus on hard work and accumulation of material objects isthat it keeps us away from supreme bliss. Madhu Kaitabha's attack on Brahma andVedas is symbolic of that. Vedas symbolize the supreme and liberating knowledgeof self and Brahma, the carrier of Vedas, symbolizes the sadhana to achieve thesupreme knowledge. The focus on working like honeybees and accumulating materialobjects tries to kills one's ability to do sadhana and obtain supreme knowledgeof self.
Vishnu battles Madhu Kaitabha for 5,000 years. Devi Bhagavatam even describesthat Vishnu wondered in the middle how to defeat Madhu Kaitabha, as He findsthem quite formidable! Even when the sattva in us awakens, it is difficult forit to overcome the formidable instinct to lead the life of a honeybee and toaccumulate the material objects for oneself and others.
When Madhu Kaitabha finally agree to be slain by Vishnu, they ask Him to killthem in a place where there is no water. They see that there is water all aroundand think that there is no place where there is no water. The Mooladhara,Swadhishthana, Manipoora, Anahata and Visuddhi chakras are the seats of earthy,watery, fiery, airy and ethery elements respectively. Swadhishthana chakra issupposed to control desires and hence water symbolizes desire. As long as thereis desire, it is tough to overcome the instinct of just working for materialobjects!
When they want a place that has no water, Vishnu shows his thighs. There is nowater there and only earthy element. This suggests that Parama Purusha'sMooladhara chakra is in the thighs of Vishu.
According to Parasara, thighs are seen from the 9th house of dharma. The earthyelement symbolizes the commitment and stability. The fact that earthy elementcame from the thighs of Vishnu shows that it is the dharma of sattwa gunasustaining this universe that ensures that there is commitment and stability inthis creation.
Moreover, it is apt that someone born in the ears (3rd house) of Vishnu foundend in the thighs (9th house, i.e. 7th house of death from the 3rd house) ofVishnu! Similarly, Brahma, who is born from the navel (6th house) of Vishnu should naturally find His end in the 12th house of Vishnu (feet), which is the7th house of death from the 6th house! That may be why Vishnu goes to sleep,when there is a change of Brahma.
Thus, the instinct within us to keep accumulating material objects like honeybees accumulate honey finds its end in the dharma of the sattwa guna, i.e. whenthe sattwa guna within us follows its dharma. Then we are fully awakespiritually. Naturally, the path to self-knowledge becomes open then and Brahmabecomes elated.
Thus, the story of Madhu-Kaitabha refers, allegorically, to the instinct most ofus have towards leading a "regular" life, working hard like honeybees andaccumulating objects for self and others and how that instinct needs to bedefeated by waking up the sattwa guna and allowing to perform its dharma.