Sayyiduna Ibn Abbas (may Allah be pleased with them both) said that the Prophet (peace and blessings be upon him) said: "By Allah, I will make an expedition against Quraysh! By Allah, I will make an expedition against Quraysh!" Then he remained silent for a while, then said: "In sha' Allah (if Allah wills)."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأيمان / 19927