Isaiah 19:19
In that day shall there be an altar to the LORD in the midst of the land of Egypt, and a pillar at the border thereof to the LORD. In that day shall there be an altar to the LORD in the midst of the land of Egypt, and a pillar at the border thereof to the LORD.
In that day there is to stand an altar to the Lord in the midst of Egypt and a pillar to the Lord at its border, serving as a sign, a public witness, and a center of devotion and true worship to Him in that land. The altar and pillar are God's living truth winning souls, namely the preaching in Egypt of a Saviour who delivers from the oppression of sin, while those oppressed there cry to the Lord for deliverance. The pillar is not the stone pyramid built by Egypt's heathen kings nor the Great Pyramid, and it is erroneous to take the altar and pillar to mean the Great Pyramid of Cheops whose passages, stairways, and chambers are treated as types of different periods and phases of the Gospel dispensation.
The verse belongs to Isaiah 19, which describes the revolutions and future state of Egypt. That chapter joins the prophecies foretelling that defensible and powerful Egypt would be invaded, conquered, and spoiled, would fall permanently into the hands of strangers, would become the basest of the kingdoms, and would renounce idolatry. That foretold history was fulfilled over more than twenty-four centuries through conquest by Nebuchadnezzar, then subjection to Persians, to Macedonians under Alexander, to Romans, to Saracens, to Mamelukes, and to Turks, leaving Egypt base, ruled by foreigners, and without idols. A great part of the prophecy about Egypt has already been fulfilled, while it is not said whether this particular verse has been fulfilled.
Many Jews settled in Egypt and the Scriptures were translated into Greek there about 300 years before Christ, and the resulting knowledge of God helped Egypt become home to strong Christian churches and centers that rivaled those in Rome and Asia. The verse points to the preaching of the gospel in Egypt and Assyria in New Testament times, including its later spread among people from Egypt. The prophecy is connected with the refuge Egypt gave to Joseph, Mary, and Jesus from Herod. Egypt's later distress and downfall humbled it and helped its people learn to know the Lord, which pride and prosperity had kept them from learning.
The verse is applied to establishing a witness for God in Egypt through the fruit of religious work there, and its image of a pillar at Egypt's border is applied to the small, faithful company of believers in Alexandria whose presence and work are a witness to God. It means the Lord will have an altar and true worship in the midst of Egypt, fulfilled in the baptism of willing souls in the Nile and the organizing of a church with sixteen members including an Arabian minister, which is the rising of the Sun of Righteousness in the land of the Pharaohs. The verse was fulfilled centuries ago and is not to be expected to be fulfilled in modern times. It also points to a fuller future manifestation in which the Lord will be known in Egypt and Egyptians will know Him.