Saint Jerome in his sermon on Psalm 41 gave an immortal reflection on the Trinity:
Like a deer that longs for springs of water, so my soul longs for you, O God. Now just as those deer long for springs of water, so do our deer. Fleeing Egypt – that is, fleeing worldly things – they have killed Pharaoh and drowned all his army in the waters of baptism.
Now, after the devil has been killed, they long for the springs of the Church: the Father, the Son, and the Holy Spirit.
We can find the Father described as a spring in Jeremiah: They have abandoned me, the fountain of living water, to dig themselves leaky cisterns that cannot hold water.