What is the ruling on one who swore an oath by Allah repeatedly in close succession while angry, and then retracted it? And does he expiate for a single oath, given his ignorance of the number of times?

If a person repeats an oath several times to emphasize a single matter, then only one expiation is due if he breaks it, whether the oaths were made in one sitting or in separate sittings. However, if by repeating the oath he intended to establish each oath as separate, then an expiation is due for each oath, and his intention determines the number of expiations. He is permitted to retract his oath and expiate for it if he deems something else better than it.