Verse 5.16.1

अथ होवाच बुडिलमाश्वतराश्विं वैयाघ्रपद्य कं त्वमात्मानमुपास्स इत्यप एव भगवो राजन्निति होवाचैष वै रयिरात्मा वैश्वानरो यं त्वमात्मानमुपास्से तस्मात्त्वंरयिमान्पुष्टिमानसि ॥ ५.१६.१ ॥

atha hovāca buḍilamāśvatarāśviṃ vaiyāghrapadya kaṃ tvamātmānamupāssa ityapa eva bhagavo rājanniti hovācaiṣa vai rayirātmā vaiśvānaro yaṃ tvamātmānamupāsse tasmāttvaṃrayimānpuṣṭimānasi || 5.16.1 ||

1. The king then said to Buḍila Āśvatarāśvi, ‘O Vaiyāghrapadya, whom do you worship as the Self?’ Buḍila replied, ‘I worship water, revered king.’ The king said: ‘That which you worship as the Vaiśvānara Ātman is named Rayi [wealth]. This is why you are rich and healthy’.

Word-for-word explanation:

Atha, next; ha uvāca, he [the king] said; buḍilam āśvatarāśvim, to Buḍila Āśvatarāśvi; Vaiyāghrapadya, O Vaiyāghrapadya; kam, whom; tvam ātmānam upāsse iti, do you worship as the Self; bhagavaḥ rājan, revered king; apaḥ eva iti, [I worship] water; ha uvāca, [the king] said; yam tvam ātmānam upāsse, the Self which you worship; eṣaḥ, this [water]; vai, for sure; ātmā vaiśvānaraḥ, is the Vaiśvānara Ātman; rayiḥ, as Rayi [wealth]; tasmāt, therefore; tvam, you; rayimān puṣṭimān asi, are rich and have a strong, healthy body.

Commentary:

Water is ‘wealth’ (rayi) because it is from water that we get food and all the good things we need.