Syriac Patrology, Volume 1: The Demonstrations of Aphrahat

and in perpetuity, to be found upon the earth, as it is written: "The righteous man shall not fail before the eyes of the Lord, nor shall the world be destitute of the upright Proverbs 2:21." And the Savior Himself bears witness to this: "I did not come to call the righteous, but sinners to repentance Luke 5:32." For Christ came, desiring that sinners be justified; for "the healthy did not need a physician Luke 5:31," since they were not laboring under any sickness. Nor did those who were satisfied hunger for Him, or desire to drink and be refreshed. He Himself cried out: "Everyone who thirsts, let him come to me and drink John 7:37." And the prophet cried out and said: "O all who thirst, come to the waters, and buy for yourselves, without silver and without price, wine and milk Isaiah 55:1," wine that gladdens, and milk that nourishes, of which the Apostle says: "As to infants in Christ, I have given you milk to drink 1 Corinthians 3:1-2."

9. Now, this is a great mystery that the prophet announced. For he said: "Everyone who thirsts, let him come to the waters." And He who fulfilled the prophets said: "Everyone who thirsts, let him come and drink." The prophet directed people to a fountain, but He who provides the drink called them to drink. The prophet cries: "Approach and drink, without price, wine and milk, from Him whose eyes are red from wine, and whose teeth are white from milk—"

as it is written, the son of man goes according to his time; and the righteous shall not be removed from before the eyes of the Lord, nor shall the world be without the upright.
Regarding this, our Savior testifies: "I did not come to call the righteous, but sinners to repentance." For He came to justify sinners, like a physician, because the healthy are not in need of a physician, since they have no sickness; and because those who were satisfied did not hunger for Him, and those who were not thirsty did not drink from Him and find rest.
He Himself cried out and said: "Everyone who is thirsty, let him come to me and drink." And the prophet cried out and said: "O all you thirsty ones, come to the waters, and buy for yourselves, without silver, wine and milk; wine that gladdens, and milk that nourishes." And the Apostle says of this: "As to infants in Christ, I have fed you milk."

(9) There is, indeed, a great mystery of the prophet.
For he said: "Everyone who is thirsty, let him come to the waters."
And the fulfiller of the prophets said: "Everyone who is thirsty, let him come and drink." The prophet commanded the fountain,
and the One who gives drink called to the drinking. And the prophet cried out: "Approach and drink, without price,
wine and milk, from Him whose eyes are beautiful or sparkling
from wine, and whose teeth are white from milk."