Dighanikaya 3.287

3.287

Evaṃ vatvā pana yasmā buddhānaṃ nisinnānaṃ vā nipannānaṃ vā koci lakkhaṇaṃ pariyesituṃ na sakkoti, ṭhitānaṃ pana caṅkamantānaṃ vā sakkoti. Āciṇṇañcetaṃ buddhānaṃ lakkhaṇapariyesanatthaṃ āgatabhāvaṃ ñatvā uṭṭhāyāsanā caṅkamādhiṭṭhānaṃ nāma, tena bhagavā uṭṭhāyāsanā bahi nikkhanto. Tasmā atha kho bhagavātiādi vuttaṃ.

Having spoken thus, however, because no one is able to search for the marks of Buddhas when they are seated or lying down, but is able [to do so] when they are standing or walking back and forth—and this is customary for Buddhas: knowing that someone has come to search for the marks, they rise from the seat and undertake the walkway—therefore the Blessed One rose from the seat and stepped outside. For that reason it is said: ‘Then the Blessed One,’ and so forth.