Kaccayanagotta Sutta is a discourse on Right View and the Middle Way. Nagarjuna quoted Kaccayanagotta Sutta in his work Fundamental Verses on the Middle Way:
“Everything exists”: That is one extreme.
“Everything doesn’t exist”: That is a second extreme.
Avoiding these two extremes,
The Tathagata teaches the Dhamma via the middle. – Kaccayanagotta Sutta
Other than that, there are numerous Pali canon texts that point out the emptiness of all phenomena:
Kyle Dixon posted:
Not by the Buddha.
I’m not sure who told you that. The Buddha states clearly in the Pheṇapiṇḍūpama Sutta SN 22.95:
Form is like a lump of foam; feeling is like a bubble; perception seems like a mirage; choices like a banana tree; and consciousness like a magic trick: so taught the Kinsman of the Sun. However you contemplate them, examining them carefully, they’re void and hollow when you look at them closely. Concerning this body, he of vast wisdom has taught that when three things are given up, you’ll see this form discarded. Vitality, warmth, and consciousness: when they leave the body, it lies there tossed aside, food for others, mindless. Such is this process, this illusion, cooed over by fools. It’s said to be a killer, for no substance is found here.
And Udānavarga 2.18:
He who has perceived that this body is (empty) as a vase, and who knows that all things (dharma) are as an illusion, does thus destroy the chief of Māra's flowers, and will no more be seen by the king of death. He who has perceived that this world is like froth, and who knows that all things are as an illusion, does thus destroy the chief of Māra's flowers, and will no more be seen by the king of death. He who has perceived that this body is like froth, and who knows that all things are as an illusion, does thus destroy the chief of Māra's flowers, and will no more be seen by the king of death.
And SA 265:
Monks, it is just as if a master magician or the disciple of a master magician at a crossroads creates the magical illusion of an elephant troop, a horse troop, a chariot troop, and an infantry troop, and a clear-sighted person carefully examines, attends to, and analyses it. At the time of carefully examining, attending to, and analysing it, he finds that there is nothing in it, nothing stable, nothing substantial, it has no solidity. Why is that? It is because there is nothing solid or substantial in a magical illusion.
And then obviously Śākyamuni is even more liberal with the use of “illusion” in describing the nature of phenomena in the prajñāpāramitā and the Vajrayāna tantras, namely the Guhyasamāja and Kalācākra which are his teachings.