This teaching is from the section The Planes of Realization of the book “In the Buddha’s Words” by Bhikkhu Bodhi.

For someone who has seen the truth of awakening, the suffering eliminated is like the great earth; what remains is like the dust on the tip of a fingernail.

Thus have I heard - at one time, the Blessed One was residing in Jeta’s grove in Sāvatthi, at Anāthapiṇḍika’s park.

Then the Blessed One, having taken a small amount of dust on the tip of a fingernail, addressed the monks: “What do you think, bhikkhus, which is more, this small amount of dust on the tip of a fingernail or this great earth?”

“Indeed, venerable sir, the great earth is more. The small amount of dust on the tip of the fingernail put by the Blessed One does not come to a hundredth part, nor to a thousandth part, nor to a hundred-thousandth part compared to the great earth.”

“Just so, bhikkhus, for the disciple of the noble ones who has attained right view, who has completely penetrated the four noble truths, this much greater is the suffering that is exhausted and consumed; only a small amount remains. It does not come to a hundredth part, nor to a thousandth part, nor to a hundred-thousandth part of the former mass of suffering that is exhausted and consumed compared to this final state of having at most seven more existences. Thus great, bhikkhus, is the realization of the Dhamma; thus great is the attainment of the vision of the Dhamma.”

Related Teachings:

What is the stream and who is a stream-enterer (SN 55.5) - A dialogue between the Buddha and Sāriputta on the four factors for stream-entry: 1.) association with good people, 2.) hearing the true teaching, 3.) wise attention, and 4.) practice in accordance with the teaching. Sāriputta also defines the “stream” and the “stream-enterer” and the Buddha approves of his answer.

Steps toward the Realization of Truth (MN 95) ↗️ - Here, the Buddha shares the key aspects of how one awakens to the truth of awakening - by first understanding (preserving) it, and how one arrives at the truth through building a life practise of the truth that one has awakened to.

Entering the Fixed Course of Rightness (SN 25.1) - The Buddha is sharing here is that an individual who either has experiential confidence in his teachings or has cultivated a partial degree of wisdom through independent verification will not die without having realized the fruit of stream-entry. Plus, a list of teachings a stream-enterer would’ve verified as they gradually awaken to the truth of enlightenment.