Paccanika Sutta  (SN 7:16)

On one occasion the Blessed One was staying near Sāvatthī in Jeta’s Grove, Anāthapiṇḍika’s monastery. And on that occasion a brahman named Paccanikasāta (Enjoyer of Contradiction) was living in Sāvatthī. Then the thought occurred to the brahman Paccanikasāta, “Let’s go to the contemplative Gotama and contradict whatever he says.”

Now, at that time the Blessed One was doing walking meditation in the open air. So the brahman Paccanikasāta went to the Blessed One and, following behind the Blessed One as he was doing walking meditation, said to him, “Speak Dhamma, contemplative.”

The Buddha:

“What’s well-spoken

isn’t easy to understand

by one who enjoys contradiction,

who’s defiled in mind,

intent on confrontation.

But whoever has subdued confrontation

& suspicion in his awareness,

who has relinquished hatred:

He will understand

what’s well-said.”

When this was said, the brahman Paccanikasāta said to the Blessed One, “Magnificent, Master Gotama! Magnificent! Just as if he were to place upright what was overturned, to reveal what was hidden, to show the way to one who was lost, or to carry a lamp into the dark so that those with eyes could see forms, in the same way has Master Gotama—through many lines of reasoning—made the Dhamma clear. I go to Master Gotama for refuge, to the Dhamma, & to the Saṅgha of monks. May Master Gotama remember me as a lay follower who has gone for refuge from this day forward, for life.”

See also: MN 18; AN 5:151; AN 6:86–88; Sn 4:8; Thag 5:10