This book shows that this hatred goes way back.
From "Customs and traditions of Palestine: illustrating the manners of the ancient Hebrews", by Ermete Pierotti.
In Palestine, as in the whole of Syria, especially among the ignorant Christian population, a most unfortunate prejudice is current, that the Jews, just before their Passover, try to get hold of Christians, especially of children, in order to mix their blood with unleavened bread; since, without this condiment, it would not be prepared according to the directions in the law of Moses. Unhappily this absurd fancy is not scouted as it ought to be by too many of the priests and monks of the Eastern Churches; so that sometimes the Jews are exposed to insults which give rise to serious disturbances, without having afforded by their conduct the slightest ground for such an imputation. If the Eastern clergy studied their Bibles, they would soon discredit these fables; but, as few of them know anything about that book, they are not the persons to abolish prejudices, which they foster by their preaching to the faithful from morning to night; certainly they cannot know that it was the blood of a lamb, not of a man, which was to be sprinkled on the door-posts and lintel1, and they even seem to believe that heathen leeches prescribed baths of children's blood as a cure for leprosyz; perhaps too they have heard of some Rabbinical books' in which it is said that Pharaoh bathed in the blood of children to cure his leprosy, and that his magicians ordered the same remedy for another disease, and have transformed Pharaoh into a Jew, and the children into Christians.
This is no exaggerated accusation, for I have heard greater absurdities from the lips of the Greek and Armenian monks in Jerusalem: for example, they have shewn me the place where Melchizedek planted the first olive after the Deluge, and where he first made bread, and a thousand similar absurdities.
However I will give an instance of the popular belief in this falsehood, which fell under my own notice. One day in 1858, on going out of my house in Jerusalem, I saw a very respectable Jew running at full speed, pursued by some Arabs, who as soon as he reached me claimed my protection against his assailants. These tried to drag him away from me; I asked what was the matter; but had only yells and incoherent exclamations in reply; so I determined to place the Jew inside my own doors for security. The Arabs, however, resisted, and though I was close to home I should not have been able to defend him had not my European servants arrived upon the scene; this reinforcement turned the tide of battle, and the enemy quickly fled, not without torn beards and conspicuous bruises from our cudgels, as a warning for the future.
When I got the Jew safe within, he told me the reason of the disturbance. As he was walking through the town he found a little boy crying, and stopped to ask what was the matter. He found that the child had lost his way, so he took him by the hand and went to help him to find his home. Some men, however, came up, and rudely snatched the child from him, saying, " You have taken him to kill him, and you shall smart for it!" Thereupon he took to flight, and happily met me.
After hearing this I returned to the street and found that the vanquished enemy had returned with reinforcements, and were waiting to demand the Jew from me. I shewed them very plainly, more by actions than words, that they were not going to have him; and to pacify them suggested that I would take him to the governor to be imprisoned. This proposal was joyfully accepted. I took the frightened man, and, accompanied by the Arabs, went to the governor's house; where I placed them all in the custody of the police, and then went to see Surraya pasha. I informed him what had happened, and after a short examination the Jew was released and the Arabs sent to prison.
On Good Friday the Jews cannot quit their own quarters, as the Latins, Greeks, and Armenians would insult and otherwise illtreat them. On some occasions the pasha has been obliged to guard the entrances of their streets with bodies of soldiers and police to protect them from the fanatical Christians, who would have made an attack upon them. No Jew, who lives at Jerusalem, dares to pass in front of the court of the Church of the Holy Sepulchre, for he well knows how great a risk he runs of suffering for his curiosity. If, on an occasion like this, he were murdered, the malefactors would not be severely punished; for all the native population unfortunately hold the opinion that to injure a Jew is a work well pleasing in the sight of God. This is due to the fact that the Jews, although numerous, do not know how to make themselves respected; and to the sermons constantly delivered by the Latins, Greeks, and Armenians, in which the most opprobrious and unseemly epithets are heaped upon them, even in the churches themselves, and of course still more in less sacred places. These are all believed by the faithful, who are thus excited by their priests to insult all whom they meet. Again, the poorer Jews when going or returning from pilgrimages between Jerusalem and Hebron, avoid passing through Bethlehem to escape the insults which the "good Christians" of that place, excited by their monks, always inflict upon them. The rich, however, are free from all these inconveniences, for the bakhshish which they liberally distribute soothes down all party spirit; so that they are not only tolerated, but even honourably entertained in the convents of these Christians, their liberality making them welcome guests to both monks and people. They can visit the Tomb of Christ, the mosques and churches in Jerusalem itself, and be received everywhere with respect, paid not to their personal excellencies, but to their gold. Some of the wealthier members of the Jews now in England know full well that this is true.