While he was on the pulpit of Egypt, he said, "I heard the Messenger of Allah ﷺ say, 'It is not lawful for a man to sell against the sale of his brother until he abandons it.'"
حدثنا يعقوب قال حدثنا أبي عن ابن إسحاق قال حدثني يزيد بن أبي حبيب المصري عن عبد الرحمن بن شماسة التجيبي قال سمعت
وهو على منبر مصر سمعت رسول الله ﷺ يقول لا يحل لامرئ يبيع على بيع أخيه حتى يذره
Its isnad is sahih. Abdul-Rahman bin Sahammasa Masri Mahri is a well-known reliable narrator, and his hadith appears in Muslim 2/103, no. 1414, Ibn Majah 2/755, no. 2246, Abu Yaala 3/298, no. 1762, and Bayhaqi 7/180.