Shatapatha Brahmana 11.1.6.23

11.1.6.23

atha pratīcīṃ diśamapaśyan tāmāśāmakurvata tasmādyatprāṅ sṛtvā vindata etāmeva tena diśametyāśāṃ hyetāmakurvatopaināmitaḥ kurvīmahīti tāṃ śriyamakurvatemāṃ khalu śriyam paśyemeti seyam pṛthivyabhavacrīrvā iyaṃ tasmādyo'syai bhūyiṣṭhaṃ vindate sa eva śreṣṭho bhavati

They then beheld the western quarter, and made it (to represent) hope,--wherefore it is only when, after going forwards (to the east), one obtains (his object) that he goes (back) to that (western) quarter; for they (the gods) made that (quarter to represent) hope. 'Let us improve it from here!' they said, and made it to be prosperity (or distinction). 'May we see this prosperity!' they said; and it became this earth, for this (earth) is indeed (the source of) prosperity; whence he who obtains most therefrom becomes the most prosperous.