Four divisions of Gayatri Mantra is nothing but the break up of the whole Gayatri Mantra into four divisions for a better understanding of the reader. There are actually no such divisions in the Gayatri Mantra written in Sanskrit Language which reads "Aum bhoor bhuwah swaha, Tat savitur varenyam Bhargo devasaya dheemahi Dhiyo yo Naha prachodayat". These slokas in Sanskrit are elaborately explained by breaking the same into four Parts. The first part or division of the Gayatri Mantra is "Aum Bhur Bhuvah Swah", the second part is "Tat Savitur Varenyam", the third part is "Bhargo Devasya Dhimahi" and the fourth part is "Dhiyo Yo Nah Prachodayat".
"Aum bhoor bhuwah swaha" is the first of the four divisions of the Gayatri Mantra in which `Aum` the Supreme name of God and the words `bhoor bhuwah swaha` collectively means `Mahavyahriti`. These words express the nature of God, and present his inherent qualities. Mahavyahriti is summed up by comparison to the word Aum itself, and by this comparison, it can be compared to the true nature of God, which distinguishes him from other two entities acknowledged in that structure (namely, soul and matter), in the same manner as the comparison between the three parts of the word Satchidananda, which is another name used to describe God.
"Tat Savitur Varenyam" forms the second part from among the four parts of the Gayatri Mantra. Here `Tat` is used to denote that the worshipper is referring to God, and his praise being offered to God is purely aimed at the Almighty, without acquiring any personal gain from that praise. Savita, from which the word `Savitur` has been derived, is another name for God, and for this reason that the Gayatri Mantra is also called the Savitri Mantra. The inference of Savita is of God`s status as the spring, the source of all things. It is through the divine grace of God that the Universe exists, and therefore this word ends the Mahavyahriti, by describing the ability of God to form the Universe and sustain it, and at the right time, produce its dissolution. The word, `Varenyam` means our acceptance of God, and the same can also be translated to mean the one who is worthy. The one who is always ready to get all the world`s material riches, more often than not, get disappointment once he achieved the same. However, God is the one who, once achieved and realized, possesses the ability to truly satisfy.
"Bhargo Devasya Dhimahi" is also one of the parts of the Gayatri Mantra. It further describes the qualities and attributes of God, his instrumental and functional qualities, rather than intrinsic qualities, and through these qualities we find his relationship with us.
The last part or division of the Gayatri Mantra is "Dhiyo Yo Nah Prachodayat" and it praises and glorifies God and thanks God. It also asks God to forgive us from all sins. After all the three divisions of the Gayatri Mantra, this division is our request from God. As our soul is the Light of Life within us, and which acts on our body through the medium of the brain, we request God to make this contact righteous and pure. The soul is pure since it is divine in nature and the body is completely under the control of the mind. The mind forms the link, which is affected by the soul as well as the outer world. This last part of the Gayatri Mantra we ask God to help us improve our intellect, and provide us proper guidance in the right direction.
The fine rhythmic patterns, solacing ancient sounds and strong intent make the Gayatri Mantra a glorious part of daily spiritual practice. The Gayatri Mantra blends the effects of mantric sound with deep and profound prayer, and thus forms a combination which is extremely potent.