The thirumanthiram (1) sung by saint thirumUlar (2) in the third tantra deals as part of the aShTanga yoga the yoga positions, known as Asanas. The word Asana means "to sit". These yogasanas describe the positions or postures at which one needs to sit while practicing yoga. These postures would make the yogi to continue the practice in a convenient way (though some of these positions appear inconvenient in the beginning, the convenience of them could be felt in due course), so that the practice could progress forward to the higher ladders in the yogic sAdhana (practice). In fact these positions have lots of spiritual significance and hence lots of importance is attached to these sitting positions in Yoga. Given the significance of these postures, they need to be learnt well from a knowledgeable teacher and practiced.
The following are the English translations/meaning of the mantras on Asanas from thirumandhiram.
Starting with padmAsana there are very many Asanas. Special mentioning among them are eight. Without fatigue one who stays on swastika (sukhAsanam) becomes the leader.
Put one foot on the other thigh, pulling it (so that it touches the abdomen). Thus put the second leg also over the other thigh. On this keep well the two hands. This becomes padmasanam.
Put the flawless right leg on the left thigh. Stretch the hands on the knees. Make the body stay perfect in this posture. Thus get the benefit ofbadrAsanam .
put the feet on the thigh (like padmasana). Raise the body up with the two hands kept on the ground balancing the weight of the body. Stay unperturbed in that position that becomes kukkuTa Asanam (rooster position).
(Stand on the toe). On the knees stretch the hands. (Open the mouth). Fix the sight at the tip of the nose. This is called simhAsanam
badrasana, gomukha, padmasana, kesari (simhAsana), soththiram, vIrAsana, sakAsana - these seven are the best ancient Asanas. With these there are multiple hundreds of Asanas.
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