In an article published in 1983, H. Kassis drew attention to two dinars from the end of the Almoravid period and the beginning of the Almohad Empire. One of these was minted in Ceuta in the year 542 of the hijra. The other is a dinar from the following year (543 AH), also minted in Ceuta and whose existence had been made known by F. Codera in 1903. According to Ibn Khaldun — who has nothing specific to say about the Prophet's practices regarding money — at the dawn of Islam gold and silver were used by weight in commercial transactions, even when use was made of coins such as those produced by the Persians. The value of the coins was equivalent to the "real" value of the precious metal, thus overcoming the moral and religious problem posed by the fact that coins might have a value higher than their weight.