All good deeds are done with the right hand, such as a tilak (coloured spot or mark worn by Hindus), vermillion, giving donations, or taking parsad. Generally, the left hand is used to take something which is temporarily yours, which means you have to return it. There is not much science behind it. The right hand is considered to be spiritually superior to the left hand as it is believed that the right hand is one's own while the left expresses the destiny and the traits of one's spouse.
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