Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: "For one of you to bite on a live coal until it cools, or to hold on to it until it cools, is better than for him to say about a matter that Allah has decreed: If only it had not happened."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9139