This is a quotation from Śrīmad-Bhāgavatam (1.18.13). This verse concerns the Vedic rites and sacrifices performed by the great sages of Naimiṣāraṇya, headed by Śaunaka Ṛṣi. The sages pointed out that association with a devotee for even less than a second is beyond comparison to a thousand Vedic rituals and sacrifices, elevation to heavenly planets or merging into the existence of the Supreme.