तीर्थवंशोपदेशः
Tīrtha-vaṃśa Upadeśa: Instruction on the Fruits of Sacred Waters
(मुहूर्तानां त्रय॑ पूर्वमह्नः प्रातरिति स्मृतम् । जपथध्यानादिभिस्तस्मिन् विप्रैः कार्य शुभव्रतम् ।।
bhīṣma uvāca | muhūrtānāṃ trayaḥ pūrvam ahnaḥ prātar iti smṛtam | japa-dhyānādibhis tasmin vipraiḥ kāryaṃ śubha-vratam || saṅgava-ākhyas tribhāgaṃ tu madhyāhnas tri-muhūrtakaḥ | laukikaṃ saṅgave 'rthyaṃ ca snānādi madhyame || caturtham aparāhṇaṃ tu tri-muhūrtaṃ tu pitṛyakam | sāyāhnas tri-muhūrtaś ca madhyamaṃ kavibhiḥ smṛtam || śrāddhāpavarge viprasya svadhā vai muditā bhavet | kṣatriyasya api yo brūyāt prīyantāṃ pitaras tv iti ||
Bhīṣma said: The first three muhūrtas of the day are remembered as the morning. During that time, brahmins should undertake auspicious observances—such as recitation and meditation—for their own spiritual welfare. The next three muhūrtas are called saṅgava, and after saṅgava come three muhūrtas known as midday. In the saṅgava period one should attend to worldly duties, while at midday it is proper to perform bathing and the rites of sandhyā. After midday, the next three muhūrtas are called the afternoon; this fourth portion of the day is suited to rites for the ancestors. Thereafter come three muhūrtas called evening, which the wise regard as the interval between day and night. At the conclusion of a śrāddha in a brahmin’s house, the utterance ‘svadhā’ is said to gladden the ancestors; and in a kṣatriya’s house, one should conclude by saying, ‘May the ancestors be pleased.’
भीष्म उवाच
Bhīṣma teaches a dharmic ordering of the day: allocate specific time-blocks (muhūrtas) for spiritual practice (japa, dhyāna), worldly responsibilities, purification and sandhyā rites, and ancestral duties (śrāddha/pitṛ-kārya). Right timing is presented as part of right conduct.
In the Anuśāsana Parva’s instruction-setting, Bhīṣma continues his didactic discourse by defining traditional divisions of daytime and prescribing appropriate activities for each, including how to conclude a śrāddha with role-appropriate formulas for brahmins and kṣatriyas.