Sa'id bin Jubayr narrated from Ibn Abbas, and this is not Abdullah bin Abbas (may Allah be pleased with them both) (but al-Fadl bin Abbas (may Allah be pleased with him)), that the Prophet (peace and blessings be upon him) said: "Whoever intends to perform Hajj, let him hasten, for in it an animal may go astray and something may arise."
Hadith Referenceالمعجم الكبير للطبراني / باب الفاء / 15851