The Pharisees ask for a sign
11 The Pharisees came and began to question Jesus. To test him, they asked him for a sign from heaven. 12 He sighed deeply and said, “Why does this generation ask for a sign? Truly I tell you, no sign will be given to it.” 13 Then he left them, got back into the boat and crossed to the other side.
The Yeast of the Pharisees and Herod
14 The disciples had forgotten to bring bread, except for one loaf they had with them in the boat. 15 “Be careful,” Jesus warned them. “Watch out for the yeast of the Pharisees and that of Herod.”
16 They discussed this with one another and said, “It is because we have no bread.”
17 Aware of their discussion, Jesus asked them: “Why are you talking about having no bread? Do you still not see or understand? Are your hearts hardened? 18 Do you have eyes but fail to see, and ears but fail to hear? And don’t you remember? 19 When I broke the five loaves for the five thousand, how many basketfuls of pieces did you pick up?”
“Twelve,” they replied.
20 “And when I broke the seven loaves for the four thousand, how many basketfuls of pieces did you pick up?”
They answered, “Seven.”
21 He said to them, “Do you still not understand?”
God the spring of wisdom
Saint Athanasios the Great, The epistle to Serapion, The Bishop of Thmuis, Against those who say blasphemies and say that the Holy Spirit is a creature, XIX, in Church Fathers and Writers (2000), vol. 16, pp. 44-45
„(…) The Father is called spring and light. As He says: `They left Me, the spring of living water (Jeremiah 2, 13). (…) And Saint John the Evangelist says : Our Go dis Light (I John 1, 5). And the Son in relation with the spring is called river: The river of God is filled with waters (Psalm 44, 10).
In relation with the light is radiance. As Saint Paul the Apostle says: The Son is the radiance of God’s glory and the exact representation of his being, sustaining all things by his powerful word. (Hebrews 1, 2).
The Father being the Light and the Son His radiance (as we must not tire repeating these often, it may be seen in the Son as well the Spirit in which we are enlightened. As He says:
I keep asking that the God of our Lord Jesus Christ, the glorious Father, may give you the Spirit[f] of wisdom and revelation, so that you may know him better. 18 I pray that the eyes of your heart may be enlightened in order that you may know the hope to which he has called you, the riches of his glorious inheritance in his holy people, 19 and his incomparably great power for us who believe. (Ephesians 1, 17-19).
We being enlightened by the Spirit, Christ is the One Who enlightens in Him.
9 The true light that gives light to everyone was coming into the world. (John 1, 9).
And again the Father being the spring and the Son being called the river it is said about us that we drink the spring. As it was written that we were all given the One Spirit to drink (I Corinthians 12, 13); and by being given to drink from the Spirit, we drink Christ. For they drank from the spiritual drink which was to come. And the stone was Christ (I Corinthians 10, 4). And again Christ being true Son, we, by receiving the Spirit, are made sons.`
Saint Basil the Great, Homilies and speeches, Homily XXIV, V, in Church Fathers and Writers (2009), vol. 1, p. 357
`Where is the presence of the Holy Spirit, there is present Christ as well; and where is Christ, there is evidently the Father as well. (…) Thus, being made holy by the Spirit, we receive Christ Who dwells in us in the inner man and together with Christ we receive the Father, Who dwells in the worthy ones.