The following is an excerpt from sermon by St Maximos the Confessor on this Gospel (Mk 8.1-9). It is taken from M. F. Toal's "The Sunday Sermons of the Great Fathers" (3.289-291).
Our Lord Jesus Christ in many and various ways revealed to us in the Holy Scriptures, as also in His mysteries and sacraments, the sublimity of His Divinity and the tenderness of His Humanity, so that those who ask of Him shall receive, those who seek of Him shall find, and to those who knock it shall be opened to them. For all the wonders He wrought in this world, when clothed in our frail nature, He did for us. It was not without reason the Lord did these things, nor as if were idly and without purpose. Christ is the Word of God, Who speaks to men, not in words only, but also in deeds. And furthermore, this event which is read of in the holy Gospel today seeks for the one who will understand it; and when he has understood it, joy will fill his soul.
And in this reading from the Gospel we are to consider at the same time in our one and the same Redeemer, the separate activity of both His Divinity and His Humanity; and we must detest with all our heart the error of Eutyches, who presumed to put forward as Catholic truth that in Christ there is but one sole operation. For in either case, he who says that He was only man will deny the glory of his Creator, and he who says that he is God only will deny the compassion of the Redeemer. For that the Lord had compassion on the multitude, lest they faint or hunger or through weariness of the long way to their homes, makes known to us that He possessed the tenderness and affection that belongs to human weakness; but that He fed four thousand men with seven loaves and a few fishes was, we believe, a work of divine power.
[In this Gospel], four thousand, which means that all people, from the four points of the heavens, are filled with the sevenfold grace of the Spirit unto Life eternal.
And so, beloved, we who believe in our Lord Jesus Christ, not through the Law but by faith, who are redeemed, not by its works but by grace itself; who are filled, not from the five loaves, that is, from the Five Books of Moses, but by the sevenfold grace of the Holy Spirit, as the blessed Isaias had prophesied, saying: The Spirit of wisdom, and of understanding, the Spirit of counsel and of fortitude, the Spirit of knowledge, and of piety; And he shall be filled with the Spirit of the fear of the Lord (Is 11), let us continue in this grace of the Sevenfold Spirit, in which we were called, being filled with the gift of the Holy Spirit (Acts 2.38) through our Lord Jesus Christ, Who lives and reigns in the Unity of the Holy Ghost, God for ever and ever. Amen