Shankhayanagrihyasutra 2.9.3

2.9.3

: atikrāntāyām mahā vyāhṛtīḥ sāvitrīm svastyayanāni ca japitvā /

In the same way in the morning, turning his face to the east, standing, until the disk of the sun appears.
10, 1. When (the sun) has risen, the study (of the Veda) goes on.

2.9.3.p1

: evam prātaḥ prān mukhas tiṣṭhann ā maṇḍala darśanāt /