tataścāsyāṃ tāvadavasthāyāṃ dhāraṇāṃ cittasyaikāgryatāṃ dadhadarthabodha eva vyāpṛtatvānnāsau śaknoti dharmamupadeṣṭuṃ na hīyato vyāpārān kaścitkartuṃ samarthaḥ
And therefore, in this state, maintaining one-pointedness of mind [and] being engaged only in the comprehension of objects, he cannot teach dharma, for no one is capable of performing [multiple] activities simultaneously.