My dear King, all the sons of Prajāpati Dakṣa were alike in being very gentle and obedient to the orders of their father. When their father ordered them to beget children, they all went in the western direction.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
अपृथग्धर्मशीलास्ते सर्वे दाक्षायणा नृप । पित्रा प्रोक्ताः प्रजासर्गे प्रतीचीं प्रययुर्दिशम्
apṛthagdharmaśīlāste sarve dākṣāyaṇā nṛpa | pitrā proktāḥ prajāsarge pratīcīṃ prayayurdiśam
SB 6.5.2