The fifth limb of ashtanga yoga, the eightfold path of yoga, is Pratyahara प्रत्याहार. Maharishi Patanjali has complied two sutras for pratyahara. The sutras are mentioned in the classical work on yoga, Patanjali Yoga Sutra. The first sutra defines the pratyahara and the second one talks about the fruit of practicing it.
Why it is always advised to sit in meditative pose for meditation. We have seen many hindu Gods and goddess in meditative postures in pictures. Buddha, Master in jainism, hindu sages and many saints are our spiritual heritage who has always been seen in meditative poses. WHY?