Prema vahini is a book written by Baba in Telugu. It was later translated into English and can be found here: http://www.sssbpt.info/english/vprema.htm
In Dhyana Vahini (http://vahini.org/downloads/dhyanavahini.html), Swami describes in the most unequivocal manner the meaning of the word dharma in every context. It is a text that needs some attention to read and requires considerable contemplation and honesty in practice. Here is an excerpt from the chapter 7. The meaning of Gayatri. It describes in terms of sanctifying one’s daily life what are the four essential duties of man when it comes to prayer and meditation.
What exactly is sandhya? San means well and dhya is derived from dhyana, so sandhya refers to proper or intense meditation (dhyana) on the Lord. It means concentration on the Godhead. To fix the mind on God, the activities have to be controlled. For success in that process of control, one should overcome the handicaps of the qualities (gunas), the pure, passionate, and dull (sathwa, rajas, and thamas). When these forces of natural impulse predominate and try to direct along their channels, one must pray to God to negate their pull. That is the first duty of the one who strives toward God. The rule of nature is that the morning is the period of pure (sathwic) quality, the noon of passionate (rajasic) quality, and the evening hour of dusk of dull (thamasic) quality. At dawn, the mind is awakened from the comfort of sleep liberated from agitations and depressions, so the mind is calm and clear. At that time, in that mental condition, meditation of the Lord is very fruitful, as everyone knows. This is why dawn worship (praathah-sandhya) is prescribed. But, ignorant of the significance, people continue doing the ritual in a blind mechanical way, simply because the ancients laid down the rule. The second duty is to perform the dawn worship, after realizing the inner and the deeper meaning of the same.
As day progresses, one is infused with the passionate quality (rajoguna), the active effortful nature, and one enters the field of daily work and toil. Before one takes the midday food, one is directed to meditate on the Lord again and to dedicate the work, as well as the fruit derived through it, to the Lord Himself. One can start eating only after this act of devotion and grateful remembrance. This is the meaning of the noontime (maadhyamika) worship. By observing this ritual, passion is kept in check and is overpowered by the pure (sathwa) nature. This is the third duty of all people.
Then, people are possessed by a third nature, the dull (thamas). When evening descends, one hurries home, eats one’s fill, and is overpowered by sleep. But a duty still remains. To eat and sleep is the fate of idlers and drones. When the worst of the qualities (gunas), the dull (thamas), threatens to rule, one must make a special effort to escape its coils by resorting to prayer in the company of those who extol the Lord, reading about the glory of God, the cultivation of good virtues, and the purposeful nursing of good rules of conduct. This is the prescribed evening worship (sandhyavandana).
Therefore, the mind that emerges from the vacancy of sleep has to be properly trained and counseled; it must be made to feel that the bliss of meditation and the joy of being unaware of the outer world are much grander and more lasting than the comfort one gets by means of the daily dose of physical sleep. This bliss, this joy, can be felt and realized by all; discrimination will bring this home to you. This is the fourth duty of people.
People who, as long as they have life in them, observe the thrice-a-day worship are indeed of the highest type; they are ever glorious and attain all that is desired. Above all, they are liberated, even while alive (jivan-muktha).
I wanted to share this. To sanctify one’s life is to sanctify one’s body and mind. Prayer is a meditation that provides a direct connection to God and effects in creating purifying tendencies. I remember in this moment, the practices in Islam. The context of Dharma as explained by Swami here, so perfectly falls into the daily practice by people following Islam. But Baba adds that a mere mechanical practice is of no use. Therein lies the fourth duty of man, to perform the prayer with an understanding of its purpose.