Bhakti-rasāmṛta-sindhu .1.97
Blended reading (Sanskrit + English inline)
The promise of Kṛṣṇa that His devotees are never vanquished had also previously been admitted by Indra when he was defeated in the govardhana-līlā. When Kṛṣṇa stopped the villagers of Vraja (Vṛndāvana) from worshiping Indra, Indra became angry and therefore inundated Vṛndāvana with continuous rain. Kṛṣṇa, however, protected all of the citizens and animals of Vṛndāvana by lifting Govardhana Hill, which served as an umbrella. After the incident was over, Indra surrendered to Kṛṣṇa with many prayers, in which he admitted, “By Your lifting Govardhana Hill and protecting the citizens of Vṛndāvana, You have kept Your promise that Your devotees are never to be vanquished.”
The difference between satya-niyama and pratijñā is that satya-niyama is a constant vow whereas pratijñā is an occasional promise. This verse is the statement of Indra.
My note
Source: vedabase.io