Dr. Clay Trumbull has shown that the Passover was but an adaptation of the old rite which he terms the ‘Threshold Covenant.’[177] It was a rite which went back to the earliest age of mankind, and of which we find traces in many parts of the world. Even in the Egypt of to-day the building of a new house or boat is not complete without the slaughter of a sheep, the blood of which is allowed to fall on the threshold of the house or the deck and side of a vessel. The blood was the mark of the sacrifice by which the master of the house entered into covenant with the stranger, or even with his god. Where it appeared the avenging deity passed by, mindful of the covenant, and remembering that the house contained a friend and not an enemy. The threshold became an altar, and those who passed over it were made members of the family, and shared with them their rights and their religion. When once the bride had crossed the threshold of her new home, she left behind her all her old ties and relations, and became a member of a new family. To quote the words of Dr. Clay Trumbull, ‘Long before’ the night of the Exodus, ‘a covenant welcome was given to a guest who was to become as one of the family, or to a bride or bridegroom in marriage, by the outpouring of blood on the threshold of the door, and by staining the doorway itself with the blood of the covenant. And now,’ on the eve of the flight from Goshen, ‘Jehovah announced that He was to visit Egypt on a designated night, and that those who would welcome Him should prepare a threshold covenant, or a passover sacrifice, as a proof of that welcome; for where no such welcome was made ready for Him by the family, He must count the threshold as His enemy.’[178] The belief that sacrifice alone could secure the house from the wrath of Heaven has been spread widely over the world. Numberless traces of it are to be found in the folklore of Europe. Popular legend knows of bridges and castles which refused to stand until the human victim had been buried beneath their foundations, and even S. Columba was held to have been unable to build his cathedral at Iona until his companion Oran had been immured alive beneath its foundation-stones. We learn from the Old Testament that the belief was strong among the Israelites also. When Hiel of Beth-el rebuilt the ruined Jericho, we are told that ‘he laid the foundation thereof in Abiram his firstborn, and set up the gates thereof in his youngest son Segub’ (1 Kings xvi. 34). The Deity had a right to the firstborn; and if this right were not recognised by the sacrifice either of the firstborn himself or of a substitute, there could be no covenant between the family and its gods. A new building implied a new local habitation for the family and the gods it worshipped; and where there was no covenant between them, the gods would come as foes and not as friends.