From the Instructions of St Columbanus
Understand what it is that you are to drink. Let Jeremiah tell you, let the fountain himself tell you: they have abandoned me, the fountain of living water, says the Lord. So you see that the Lord himself, our God Jesus Christ, is the fountain of life; and he calls us to himself so that we may drink from him. Who will drink? Whoever loves; whoever is filled with the word of God; whoever adores enough, whoever desires enough; whoever is on fire with the love of wisdom.
See the source from which that fountain flows. It comes from the same place that the manna came from in the wilderness – for the same person is both bread and fountain, Christ our Lord and God, for whom we should always hunger. Even if we eat him, the bread, with love, even if we devour him with desire, let us still hunger for him like starving men. So when we drink him, the fountain, let us always drink him with overflowing love, filled with longing and delighting in the gentle taste of his sweetness.
For the Lord is gentleness and delight. We may eat and drink of him but still we will be hungry and thirst for more; for he is our food and drink that can never be entirely consumed. He can be eaten but there will always be more left. He can be drunk but he can never be drained dry. Our bread is eternal; our fountain lasts for ever, our fountain is sweet. So Isaiah says: come to the water all you who are thirsty; the fountain is for the thirsty, not for the surfeited. He calls the hungry and the thirsty to himself, and they can never drink enough: the more they drink, the more they desire to drink.
The word of God on high is the fountain of Wisdom. So, my brethren, it is right that we should desire it, seek it and love it. In it all the jewels of wisdom and knowledge are hidden, as St Paul says; and God calls anyone who thirsts to drink from that fountain.
If you are thirsty, drink from the fountain of life; if you are hungry, eat the bread of life. Blessed are they who hunger for that bread and thirst for that fountain; they eat and drink for ever and still they desire to eat and drink. For it is lovely above all things, that which is always eaten and drunk, always hungered and thirsted for. Thus David, king and prophet, was moved to say: taste and see that the Lord is good.