Visuddhimagga VIII-149

Asecanako ca sukho ca vihāroti ettha pana nāssa secananti asecanako, anāsittako abbokiṇṇo pāṭiyekko āveṇiko.

「纯粹与乐住」──此定之中无夹杂之物故为纯粹，不渗杂，不间杂，单独，不共。

Ñ(VIII,149): It is an unadulterated blissful abiding: it has no adulteration, thus it is unadulterated; it is unalloyed, unmixed, particular, special.

Natthi ettha parikammena vā upacārena vā santatā.

（安般念）不是由于遍作（准备定）及近行（定）而得寂静，

Ñ: Here it is not a question of peacefulness to be reached through preliminary work [as with the kasiṇas] or through access [as with foulness, for instance].

Ādisamannāhārato pabhuti attano sabhāveneva santo ca paṇīto cāti attho.

即从最初修安般念以来本来就寂静殊胜之义。

Ñ: It is peaceful and sublime in its own individual essence too starting with the very first attention given to it.

Keci pana asecanakoti anāsittako ojavanto sabhāveneva madhuroti vadanti.

然亦有人（指北寺住者）说「纯粹是无渗杂势力本来美妙」。

Ñ: But some say that it is 'unadulterated' because it is unalloyed, possessed of nutritive value and sweet in its individual essence too.

Evaṃ ayaṃ asecanako ca, appitappitakkhaṇe kāyikacetasikasukhapaṭilābhāya saṃvattanato sukho ca vihāroti veditabbo.

如是这纯粹（的安般念）每于证得安止定的剎那而获得身心之乐，故知为「乐住」。

Ñ: So it should be understood to be 'unadulterated' and a 'blissful abiding' since it leads to the obtaining of bodily and mental bliss with every moment of absorption.