22 However, she has finished her course, she has kept the faith, and now she enjoys the crown of righteousness. She follows the Lamb wherever he goes. She is filled now because once she was hungry. With joy does she sing: “as we have heard, so have we seen in the city of the Lord of hosts, in the city of our God.” O blessed change! Once she wept but now laughs for evermore. Once she despised the broken cisterns of which the prophet speaks; but now she has found in the Lord a fountain of life. Once she wore haircloth but now she is clothed in white raiment, and can say: “you have put off my sackcloth, and girded me with gladness.” Once she ate ashes like bread and mingled her drink with weeping; saying “my tears have been my meat day and night;” but now for all time she eats the bread of angels and sings: “O taste and see that the Lord is good;” and “my heart is overflowing with a goodly matter; I speak the things which I have made touching the king.” She now sees fulfilled Isaiah's words, or rather those of the Lord speaking through Isaiah: “Behold, my servants shall eat but you shall be hungry: behold, my servants shall drink but you shall be thirsty: behold, my servants shall rejoice, but you shall be ashamed: behold, my servants shall sing for joy of heart, but you shall cry for sorrow of heart, and shall howl for vexation of spirit.” I have said that she always shunned the broken cisterns: she did so that she might find in the Lord a fountain of life, and that she might rejoice and sing: “as the hart pants after the waterbrooks, so pants my soul after You, O God. When shall I come and appear before God?”
Source: Letters (New Advent)