ṢB, 5, 5, 1.2 kasmād brāhmaṇaḥ sāyam āsīnaḥ saṃdhyām upāste kasmāt prātas tiṣṭhan kā ca saṃdhyā kaś ca saṃdhyāyāḥ kālaḥ kiṃ ca saṃdhyāyāḥ saṃdhyātvam //

ṢB, 5, 5, 4.13 yat sāyaṃ prātaś ca saṃdhyām upāste tayā vīrasthānaṃ sthānaṃ ca saṃtatam avicchinnaṃ bhavati /