Musnad Abu Ya'la al-Mawsili 237:4

Surayj ibn Yunus narrated to us, Yahya ibn Zakariya narrated to us, from Yunus ibn Abi Ishaq, from Abu al-Safar, who said: Khalid ibn al-Walid descended upon al-Hirah at the command of the Marzbans (Persian governors). They said to him, "Beware of poison, lest the Persians give it to you to drink." He said, "Bring it to me." So it was brought to him. He took it in his hand, then swallowed it, and said, "In the name of Allah," and it did not harm him at all.