Daru otherwise means wood. Brahma is the mystic expression of the Lord. It is the cosmic cause and comic result of the universe. It means ever expanding and endless. Thus Daru Brahma or Daru Devata is the supreme power of the Universe. We know Lord Jagannath and other three images seated on the Ratna Singhasan of Jagannath Temple are made of wood. The wood is not any ordinary wood; it is neemwood and neem-wood is also called Daru in the interior parts of Odisha.
The greatness of Darubramha has become lively in Sarala Mahabharata. Once being enraged, king Hiranya questioned his minor son Prahallad about the existence of Lord Vishnu. Prahallad trembling with fear indicated towards a pillar of the palace as his answer. Hearing the bold answer of Prahallad, Hiranyakashiapu with much cruelity and wrath hit the pillar by his sword. Immediately, Lord Vishnu emerged out of the pillar taking the form of a lion-headed human being and mitigated the sorrows of Prahallad.
The lion-headed God is named as God Narasingha, who is also regarded as the fourth incarnation of Lord Vishnu. In his invocation, Sharala Das has described God Narasingha as Shri Jagannath. Both Lord Shri Rama Chandra and Lord Shri Krishna Chandra are also named as Kodandadhari and Dandadhari. Thus, it indicates the relation of these Lords with Daru. In the Musali Parva of Odia Mahabharat, it has been described that the hunter Jara scored an arrow to Lord Shrikrishna and the Lord breathed his last and merged with Lord Vishnu. Later, Jara and Arjuna, while started to perform the cremation of Lord Shrikrishna, they heard the heavenly voice, "set fire to my mortal remains using the log on which you would find the symbols conch, wheel, club and lotus. As per the direction, Arjun placed the body of Lord Shrikrishna on sandal wood and set fire. But the Pinda (heart) did not burn. During the event, Jara thought that Shrikrishna had earned sins during His life time and thus, the fire is unable to make His body to ashes.
While Jara was thinking deeply, again the Heavenly voice resounded, "This heart will not be gutted in fire. Immerse the body in the sea, it will be worshipped on the Neelasundar hill." After alapse of long years, a Daru was seen floating on water on the confluence of river and Bay of Bengal at Banki - Muhan near Jagannath Dham, Puri . King Indradyumna and Savar Biswabasu brought the Daru to the shore. King Indradyumna, desirous of constructing idols of Lord sighted the sacred wood according to search made as per the command of the Lord Jagannath to King Indradyumna but wood could not be sized, and form of Lords could not be conceived. But one offered flower, from the head of the deity, Kakatpur Mangala, on advice of sage Narada, was taken and touched on the sacred wood, Daru Brahma. It facilitated the splitting of wood, into three parts for construction of idols Lord Jagannath, Subhadra and Balabhadra according to requirement.
Nabakalebara (construction of New idols of the three Lords) is regular feature of Jagannath Dham at regular intervals. Old, worn out idols are rejected and buried under earth and in their place, new idols for 3 deities, i.e. Lord Jagannath, Subhadra and Balaram, are constructed. From that time, tradition, still remains that carpenter sevaks and priests living with discipline pray, Maa Mangala of Kakatpur remaining prostrated before the deity at Kakatpur to bless them by showing sacred trees and their location, which alone are suitable for construction of the idols in Nabakalebara. In fact, they get the indication, and exact location of the sacred trees and path leading to the location, in dream. This practice and custom and tradition have been existing for years together, without any deviation. Successful guidance, without fail, from the deity to find out the sacred tree, is evidence of the power and energy of Maa Mangala of Kakatpur. This is unchallenged evidence which stands unrebutted giving concrete proof of blessing, power of mother Mangala on their devotees. Even Lord Jagannath who is the hood of all universe is assisted by mother, who is the original power for creation, is actively guiding the carpenters and priests to find out suitable sacred wood, according to specific features, for construction of the sacred idols, what to speak of other evidence.