Praedicatores misericordiae (VII): Blessed Johanna of Aza

2 August, the Order of Preachers commemorates Blessed Joan (Johanna) of Aza, Saint Dominic's mother.
Rodrigo of Serrato describes her in his Chronicle of the Saints as an example of one practicing works of mercy:  

His mother showed herself to be virtuous, chaste, prudent, full of compassion for the poor and the afflicted. Among all the women of the region she was outstanding for her good reputation.
In fact his mother was most compassionate. More or less in the period that I have mentioned, she saw the sufferings of the afflicted and, having already given extensively of her property, she exhausted it by distributing to the poor the contents of a cask full of wine, a cask which was well known to the neighborhood. As her husband was returning and approached Calaruega his neighbors came up to him and some of them told him about wine which had been given to the poor.
When he arrived at home, in the presence of these neighbors Felix asked his wife to pour him some wine from the cask in question. She with no little sense of embarrassment went down into the cellar where the cask was and falling on her knees prayed to God in these words: "Lord Jesus Christ, even if I am not worthy to be heard by reason of my merits, hear me for the sake of your servant, my son, whom I have placed at your service." For this mother knew the holiness of her son. Then rising up full of faith, she immediately went to the cask and found it full of the best wine. Giving thanks to the giver of every grace, she poured some of this wine for her husband and for the others, and it flowed in great abundance. Everyone was amazed.