Water issuing from a spring is what is commonly called living water. Water collected from rain in pools and cisterns is not called living water. It may have originally flowed from a spring; yet if it collects in some place and is left to stand without any connection to its source, separated, as it were, from the channel of the spring, it is not called “living water.” Water is designated as “living” when it is taken as it flows. This is the kind of water that was in that fountain.

Saint Augustine, Tractates on the Gospel of John, 15.12, in Joel C. Elowsky (ed).  John 1-10 (Ancient Christian Commentary on Scripture)149-150.

One must investigate what is meant by “will thirst” in the statement “Everyone who drinks of this water will thirst again.” … What is meant in the first place would be something like this: he who partakes of supposedly profound thoughts, even if he is satisfied for a little while and accepts the ideas that are drawn out and that he thinks he has discovered to be most profound, will, however, when he has reconsidered them, raise new questions…. But [the Word] says, I have the teaching that becomes a fountain of living water in the one who has received what I have declared. And he who has received of my water will receive so great a benefit that a fountain capable of discovering everything that is investigated will gush forth within him. The waters will leap upward. His understanding also will spring up and fly as swiftly as possible in accordance with this briskly flowing water, the springing and leaping itself carrying him to that higher life that is eternal.

Origen, Commentary on the Gospel of John, 13.13,15-16, in Joel C. Elowsky (ed). John 1-10 (Ancient Christian Commentary on Scripture) 152.

Today, of course, is the Sunday of the Samaritan woman.

…to pray as the men of the Bible and our Fathers in faith did, means not only making certain texts one’s own, but also to assimilate all of those methods, forms, gestures, and so on, in which this praying finds its most suitable expression. This was, in any case, the opinion of the Fathers themselves, for whom this was by no means a matter of historically conditioned externals. On the contrary, they gave their full attention to these things, which Origen summarizes as follows at the end of his treatise On Prayer.

It seems to me [in light of the preceding] to be not inappropriate, in order to present exhaustively the subject of prayer, by way of an introduction, to examine [also] the [interior] disposition and the [exterior] posture that the person praying must have, as well as the place where one should pray, and the direction in which one must face in all circumstances, and the favourable time that is to be reserved for prayer, and whatever other similar things there may be.

As the Fathers themselves knew better than anyone else, one must never take Scripture out of context if one wants to understand it correctly. For the Christian this context is the Church, and the apostolic and patristic tradition gives testimony to her life and her faith. As a consequence of those breaks in tradition which have accompanied the history of the Western Church in particular, this treasure has been practically inaccessible to many today. And this is so even though we have available today an unprecedented abundance of valuable editions and translations of patristic texts. The purpose of this book is, therefore, to put into the hands of the Christians of our time the key to these treasures.

Father Gabriel (Bunge), Earthen Vessels: The Practice of Personal Prayer According to the Patristic Tradition, (Ignatius Press, 1996/2002) 14-15.

Now Christ is especially jealous for the house of God in each of us, not wishing it to be a house of merchandise or that the house of prayer become a den of thieves, since he is the son of a jealous God. … [These words] set forth the fact that God wishes nothing alien to his will to be mingled with the soul of anyone, but especially with the soul of those who wish to recive [the teachings of the] most divine faith.

Origen. Commentary on the Gospel of John, 10.221, quoted in Joel C. Elowsky (ed), John 1-10, Ancient Christian Commentary on Scripture New Testament IVa (InterVarsity Press, 2006) 102.

Today’s Gospel according to the Roman Lectionary is Saint John’s account (Jn 2: 13-25) of the cleansing of the temple.

The way of the Lord must be prepared within the heart; for great and spacious is the heart of man, as if it were a whole world. But see its greatness, not in bodily quantity, but in the power of the mind which enables it to encompass so great a knowledge of the truth. Prepare, therefore, in your hearts the way of the Lord, by a worthy manner of life. Keep straight the path of your life, so that the words of the Lord may enter in without hindrance.

Origen, Homilies on Luke 21.5.7, quoted in Thomas C. Oden & Christopher A. Hall (ed), Mark, Ancient Christian Commentary on Scripture(Intervarsity Press, 2005) 2.