Saint Gregory of Tours, in his late-6th century book titled Glory of the Martyrs (ch. 30), records the following miracles of the Apostle Andrew:
After the glorious reception of Andrew [in Paradise] many miracles are said to have been revealed either at his tomb or in various places where his relics are located. I do not think it inappropriate to relate a few of these miracles, because the edification of the Church is found in the glory of martyrs and the power of saints.
In the time when king Chlodomer of the Franks was killed, an army supplied itself by devastating Burgundy, where relics of the aforementioned martyr [Andrew] and of the martyr Satuminus were kept in a church. The church was set on fire, and already the bulk of the beams had collapsed. The poor people and the old people whom the barbarians had left behind wept and said: 'Woe to us, who today are without the assistance of such relics. If these relics are lost, we will have no more hope for the present life.' While they were weeping in this way, a man came from Tours at the command of God and shared in their grief. Once he heard about the power of the martyrs, he entered the middle of the flames, protected more by his faith than by a shield. After seizing the holy relics from the altar, he was not injured by the fire and ran outside. But suddenly he was so paralyzed that he could not walk as before. The man who was carrying the relics judged himself unworthy to do so; so he selected a guiltless young girl to carry the treasure. He hung the reliquary around her neck and quickly returned in this way to his mother city. The relics were placed in the altar of a church at Neuvy-le-Roi, where there were as yet no relics of any saints. Every year the man piously celebrated the festivals of these martyrs. After this man died, his son did not observe these festivals. When he suffered from a quartan fever for an entire year, the son vowed to construct a new church in honor of the martyrs. Once the church was completed, the fever broke and he was healed.
But I think that this did not happen without the intervention of the Divinity, because on the same day that these blessed relics were transferred to this other church, men carrying relics of St Vincentius lost their way and were brought to this village [of Neuvy-le-Roi]. Then, at the request of the priest they cut off a small piece of the relics [of St Vincentius] for him, which he placed in the holy altar from which he had removed the other relics.
During the reign of king Theudebert, Mummolus traveled to the emperor Justinian at Constantinople. As he was journeying by ship, he landed at Patras, where the same apostle [Andrew] was buried. While Mummolus waited there with his entourage, he suffered from a stone in his irritated bladder. He was doubled up with various pains and burned with a fever; he lost interest in eating and drinking and awaited only the onset of death. When he realized that he was so weak and had no hope of living, he sought to write his own will. After certifying the will with his signature and seals, he ordered inquiries to be made whether perhaps someone might be found in the city who was trained in the art of healing and who could offer assistance to a man who was about to die. When the current bishop was asked, he replied: 'How long, most beloved brothers, will you tire yourselves with pointless effort by requesting medicine from men, when there is here a celestial doctor who has often healed the diseases of ill people, not by administering herbs but by the application of his own power?' 'And who,' they asked, 'is this doctor?' The bishop replied: 'He is Andrew, an apostle of Christ.' When his servants reported this news to the suffering Mummolus, he asked to be brought to the tomb of the blessed saint. There he knelt on the pavement and earnestly prayed for what was necessary. At about midnight sleep overcame everyone present. Suddenly the ill man had the urge to attempt to urinate; he nudged one of his servants and quietly asked that a pot be brought. A pot was brought out. While Mummolus was trying to urinate, he passed a huge stone which was so solid that it clanged when it fell into the pot that had been readied. After the fever and his other pain vanished, he returned to his ship a healthy man.