The Pali term "nesajjika" means «the one who has the habit to be seated».
"nissīda" = "sitting posture"
The bhikkhu who takes up the habit to renounce to the lying posture, only adopting sitting, standing and walking postures, is called a "nesajjika". When this practice is conveniently done, with constancy and diligence, with the determination of not breaking it, we say that there is "nesajjikaṅga " (state of mind arising out of renunciation to the lying posture).
For adopting this dhutaṅga, it is convenient to pronounce the following phrase whether in Pali, whether in the language of one's choice...
«seyyaṃ paṭikkhipāmi, nesajjikaṅgaṃ samādhiyāmi.»
«I renounce to the lying posture, I will train into always remaining seated (at time of taking rest)»
According to restrictions, there do exist three kinds of practitioners of the nesajjika dhutaṅga:
The noble practitioner of the nesajjika dhutaṅga never does any of the following things, even while sleeping: 1) applying the back on something; 2) clasping the knees by means of a tissue; 3) clasping or maintaining one's knees by means of the hands or the arms.
The intermediate practitioner of the nesajjika dhutaṅga adopts one of the three things that a noble practitioner rejects.
The ordinary practitioner of the nesajjika dhutaṅga adopts two or three of the things rejected by the noble practitioner. He can put up a pillow behind his back, or sit on a chair whose upper back doesn't exceed an inclination of 45° or devoid of back.
In Buddha's time did the Miḷābhaya mahāthera, who practised the nesajjika dhutaṅga. This mahāthera was offered a high quality bed by his dāyakas. The mahāthera has trained into the development of vipassanā, while scrupulously keeping up his nesajjika dhutaṅga. In a short while, he became an anāgāmi.
Thus, it is convenient that some bhikkhus, who practise the nesajjika dhutaṅga, utilise all kinds of chairs and beds. As long as they do not lie down, they do not break their dhutaṅga.
By practising the nesajjika dhutaṅga, we can benefit with the following advantages...
Remark: the practice of a dhutaṅga alone enables one to understand its advantages.
As soon as a practitioner of the nesajjika dhutaṅga lies down and applies his head (on anything whatsoever), he breaks his dhutaṅga.
During one of the three parts of the night, the practitioner of the nesajjika dhutaṅga can stand up and walk. During this walk, the dhutaṅga cannot be broken. Among the four postures – lying, seated, standing and walking –, the lying posture alone must be given up. During the night, the practitioner of this dhutaṅga can therefore alternate between the three other postures. At time he is performing his walk, he keeps on developing his training (samatha or vipassanā). He can sleep while remaining seated during the two other parts of the night.
The devas who are harmful are afraid of an individual who remains seated well straight (in a meditative posture). When we practise this dhutaṅga, we get rid of laziness, somnolence and feelings of attachment to the pleasure given by sleep. We benefit with a great vīriya, we enjoy excellent conditions for training into kammaṭṭhāna (vipassanā or samatha). We can also develop the pīti, which eradicates sensuous desires, we experience happiness.
For these reasons, some bhikkhus observe the nesajjika dhutaṅga, which is a practice particularly propitious to the development and keeping up of vīriya. The practitioners of this dhutaṅga give a lot of prestige to the sāsana.
Origin: Book in Burmese language
Author: Monk Devinda
Translator: Monk Dhamma Sāmi
Date of translation: 2004, January
Update: 2005, June the 18th