The nobles received the king with joy, and, kneeling to kiss his hand, vowed to be true to him. The Cid alone held aloof.
'You are heir to the throne, Don Alfonso,' said he, 'but before I bend the knee to you I demand that you and twelve of your vassals shall swear that you are innocent, in deed or in word, of the blood of your brother.'
'I will swear it,' answered Alfonso, 'when and where you please, and twelve men of Leon shall swear it likewise.'
'You shall swear to me in the holy cathedral of Santa Gadea in Burgos,' said the Cid; and thither they all rode silently and solemnly, while Don Rodrigo, standing at the altar, held out the crucifix to the kneeling king. But though the oath was taken freely, both by Alfonso and his vassals, deep in the heart of the Cid lay a doubt of his truth.
'You shall swear it thrice,' he said, and Alfonso, devoured as he was with rage, knew the Cid's power too well to disobey, though his face grew pale with wrath.
'You shall answer for this,' he cried as he rose to his feet, and from that day the king never ceased to seek for an excuse to compass Don Rodrigo's banishment. At last he found one.
The Moorish king of Toledo laid a complaint against the Cid that, in spite of his alliance with Alfonso of Castile, his lands had been ravaged and his people made captive. Well Alfonso knew that it was the Moors themselves who had broken faith with him, and had wasted the Spanish territories which lay along their borders, but he eagerly snatched at the plea, and bade the Cid go, an exile, from Castile, while his possessions were declared forfeit.
With every insult heaped on him that the king could invent, the Cid left the city and rode to his castle of Bivar, only to find that his enemies had been before him and had stripped it bare, while his wife and children had sought refuge in the convent of San Pedro de Cardeña.
It was on his way thither that the Cid in his dire distress did the one mean deed recorded of him, which he never ceased to bewail during his life, and afterwards on his deathbed. He had reckoned on finding money for his needs at Bivar, and there was none, and he knew not what to do. In this strait he invited two rich Jews to his tent under the walls of Burgos, and, pointing to two large chests which stood on the ground, he told the Jews that they were filled with silver plate, and begged that they would take them, and give him a thousand crowns in exchange. The Jews, used though they were to being cheated and despoiled by Christians, yet trusted to the honour of the Cid, and counted out the money. Then, placing the coffers on the backs of two stout mules, they returned with them into Burgos, first promising that they would not open them till a year had passed. At the time appointed they lifted the lid, and, behold, the coffers were full of sand!'