Acts such as sacrifices, gifts, austerities etc., enjoined in the Vedas should not be relinquished by the aspirant for release, but should be performed day after day until his death. Why? Acts like sacrifices, gifts and austerities associated with the different stations of life, are the means of purification for the wise., i.e., for those given to contemplation. Contemplation is worship. For the aspirants who perform such worship (Upasana) throughout their lives, they (sacrifices etc.) are a help to erase the previous Karmas which stand in the way of the fulfilment of such worship.