Vivekachudamani 13

arthasya niscayo drsto vicarena hitoktitah | 
na snanena na danena pranayamasatena va || 
(Sankaracarya's Vivekachudamani 13) 

Neither sacred baths nor any amount of charity nor even hundreds of pranayamas* can give us the knowledge about our own Self. The firm experience of the nature of the Self is seen to proceed from inquiry along the lines of the salutary advice of the wise. 

Charity is sometimes performed for elevation to the heavenly kingdom and sometimes with great trouble and with repentance afterward: "Why have I spent so much in this way?" Charity is also sometimes given under some obligation, at the request of a superior. These kinds of charity are said to be given in the mode of passion. 

Contributions for indulgence in intoxication and gambling are not encouraged here. That sort of contribution is in the mode of ignorance. Such charity is not beneficial; rather, sinful persons are encouraged. Similarly, if a person gives charity to a suitable person but without respect and without attention, that sort of charity is also said to be in the mode of darkness. 

There are many charitable foundations that offer their gifts to institutions where sense gratification goes on. Such charities are not recommended in the Vedic scripture. Only charity in the mode of goodness is recommended. 

It has been explained that penance, sacrifice, charity, and foods are divided into three categories: the modes of goodness, passion, and ignorance. But whether first class, second class or third class, they are all conditioned, contaminated by the material modes of nature. When they are aimed at the Supreme — oḿ tat sat, the Supreme Personality of Godhead, the eternal — they become means for spiritual elevation. In the scriptural injunctions, such an objective is indicated. These three words, oḿ tat sat, particularly indicate the Absolute Truth, the Supreme Personality of Godhead. In the Vedic hymns, the word oḿ is always found. 

One who acts without following the regulations of the scriptures will not attain the Absolute Truth. He will get some temporary results, but not the ultimate end of life. The conclusion is that the performance of charity, sacrifice and penance must be done in the mode of goodness. Performed in the mode of passion or ignorance, they are certainly inferior in quality. The three words oḿ tat sat are uttered in conjunction with the holy name of the Supreme Lord, e.g., oḿ tad viṣṇoḥ. Whenever a Vedic hymn or the holy name of the Supreme Lord is uttered, oḿ is added. This is an indication of Vedic literature. These three words are taken from Vedic hymns. Oḿ ity etad brahmaṇo nediṣṭhaḿ nāma (Ṛg Veda) indicates the first goal. Then tat tvam asi (Chāndogya Upaniṣad 6.8.7) indicates the second goal. And sad eva saumya (Chāndogya Upaniṣad 6.2.1) indicates the third goal. Combined they become oḿ tat sat. Formerly when Brahmā, the first created living entity, performed sacrifices, he indicated by these three words the Supreme Personality of Godhead. Therefore the same principle has always been followed by disciplic succession. So this hymn has great significance. Bhagavad-gītā recommends, therefore, that any work is done should be done for oḿ tat sat, or for the Supreme Personality of Godhead.