The bodhisatva Śailaśikharasaṃghaṭṭanarāja said: “Just as the wind enters through a chink, just so the Māra can find a weak point where there is a chink in thought. The bodhisatva therefore should not have any chink in his thought. Here, the thought without chink is, that is to say, to fulfill the emptiness endowed with all sorts of excellencies (tadyathāpi nāma cchidrān mārutaḥ praviśati evam eva yato yata eva cittasya cchidraṃ bhavati tatas tata eva māro ’vatāraṃ labhate | tasmāt sadā ’cchidracittena bodhisattvena bhavitavyaṃ tatreyam acchidracittatā | yad idaṃ sarvākārajñatāyāḥ śūnyatāyāḥ paripūrir). This is the gate to the light of the dharma (dharmālokamukha) that the bodhisatva transcends the sphere of the Māra.”

Quotation from ŚikṣMS 60b5-7; B 117,7-10; ŚikṣTib(D) 67b1-3; ŚikṣChi(T.1636) 97c27-98a1.

ŚikṣMS: āryagaganagañjasūtre ’py uktaṃ (6) tadyathāpi nāma cchidrān mārutaḥ praviśati evam eva ‹yato›¹ yata eva cittasya cchidraṃ bhavati tatas tata eva māro ’vatāraṃ labhate tasmāt sadā ’cchidracittena bodhisattvena bhavitavyaṃ tatreyam acchidracittatā | yad idaṃ sarvvākārajñatāyāḥ śūnyatāyāḥ pari(7)pūrir iti |
ŚikṣTib: ’phags pa nam mkha’ mdzod kyi mdo las kyaṅ | ’di lta ste dper na bu ga nas rluṅ ’jug pa de bźin du gaṅ daṅ gaṅ nas sems la skyon byuṅ ba de daṅ de ñid nas bdud kyis glags rñed do || de lta bas na byaṅ chub sems dpa’ rtag tu sems la skyon med par bya’o ||
ŚikṣChi: 又虚空藏經云譬如孔隙聲入其中。菩薩亦爾。若心有間隙則魔得其便。是故菩薩令心常無間隙。若心無間隙。則諸相圓滿。及空性圓滿。