Among all ancient peoples, sacrifice remained the chief form of communion with God, whether the question was of the One God or of pagan gods. So in the court of the Tabernacle...
Among all ancient peoples, sacrifice remained the chief form of communion with God, whether the question was of the One God or of pagan gods. So in the court of the Tabernacle there was to be a special altar which, like the whole Tabernacle, was light enough to be moved, if necessary, together with the tent.
The court was necessary because sacrifices were always made under the open sky; inside a building, and still more inside a tent, it would be at least problematic to kindle a sacrificial fire. At the same time, altars usually appeared not where it was convenient for people, but where divine power had in some way manifested itself, whether the power of some pagan god or spirit or the power of the One. Such places, properly speaking, were called sacred in antiquity: divine power sanctified them.
If a place was not sacred, there was no point in building an altar or sacrificial altar there; it was assumed that gods and spirits visited only familiar places, where they could be met. The first Yahwistic altars in Palestine appeared on the same basis: a theophany, a manifestation of God, was necessary in order for an altar to appear at its site. Of course, there was still much here that was pagan, but human consciousness in general does not change very quickly. Besides, one has to take into account that before the coming of Christ, God truly was not present everywhere, and at that time He chose the places of His presence, from the human point of view, in roughly the same way pagan gods and spirits did.
In reality God had His own plan for the places where He manifested His presence, and that plan had nothing to do with any human considerations. But for human beings it sometimes looked as if God arbitrarily appeared now here, now there, like pagan gods and spirits. As for Sinai, there, as in Egypt, there could by definition have been no traditional Yahwistic altars.
Neither Egypt nor Sinai was God's land in the sense in which the land promised by God to Abraham was. God's presence was "at home" only there, in God's land, intended by God for His people. In the wilderness, however, God accompanies His people without having a permanent home there, just as those whom He is leading have none there. That is why only a portable sanctuary is possible here, until the arrival in that land about which Abraham had already been promised that it would belong to his descendants.