Albert Barnes Commentary Luke 5:39

"And no man having drunk old [wine] desireth new; for he saith, The old is good." — Luke 5:39 (ASV)

Having drunk old wine, and so on. Wine increases its strength and flavour, and its mildness and mellowness, with age, and so the old is preferable. Those who have tasted such mild and mellow wine would not readily drink the comparatively sour and astringent juice of the grape as it came from the press.

The meaning of this proverb here seems to be this: You Pharisees wish to draw my disciples to the austere and rigid duties of the ceremonial law—to fasting and painful rites; but they have come under a milder system. They have tasted the gentle and tender blessings of the gospel; they have no relish for your stern and harsh requirements.

To insist now on their observing these duties would be like telling a man who had tasted good, ripe, and mild wine to partake of what is sour and unpalatable. At the proper time, all the sterner duties of religion will be properly regarded; but at present, to teach them to fast when they see no occasion for it—when they are full of joy in their Master's presence—would be like putting a piece of new cloth on an old garment, or new wine into old bottles, or drinking unpleasant wine after one has tasted what was more pleasant. It would be ill-timed, inappropriate, and incongruous.