How we cite our quotes:
Quote #1
When the adversaries of Judah and Benjamin heard that the returned exiles were building a temple to the Lord, the God of Israel, they approached Zerubbabel and the heads of families and said to them, "Let us build with you, for we worship your God as you do, and we have been sacrificing to him ever since the days of King Esar-haddon of Assyria who brought us here." But Zerubbabel, Jeshua, and the rest of the heads of families in Israel said to them, "You shall have no part with us in building a house to our God; but we alone will build to the Lord, the God of Israel, as King Cyrus of Persia has commanded us." Then the people of the land discouraged the people of Judah, and made them afraid to build, and they bribed officials to frustrate their plan throughout the reign of King Cyrus of Persia and until the reign of King Darius of Persia. (NRSV Ezra 4:1-5)
Now when the adversaries of Judah and Benjamin heard that the children of the captivity builded the temple unto the Lord God of Israel; then they came to Zerubbabel, and to the chief of the fathers, and said unto them, Let us build with you: for we seek your God, as ye do; and we do sacrifice unto him since the days of Esarhaddon king of Assur, which brought us up hither. But Zerubbabel, and Jeshua, and the rest of the chief of the fathers of Israel, said unto them, Ye have nothing to do with us to build an house unto our God; but we ourselves together will build unto the Lord God of Israel, as king Cyrus the king of Persia hath commanded us. Then the people of the land weakened the hands of the people of Judah, and troubled them in building, and hired counsellors against them, to frustrate their purpose, all the days of Cyrus king of Persia, even until the reign of Darius king of Persia. (KJV Ezra 4:1-5)
Here's the first indication of what's to come: the separation of the returned exiles from the other people living in Judea. It's like, "Hands off our temple." The adversaries start making trouble because they see what's happening and succeed in stalling the building project. They present themselves as worshippers of the Israelite god, but the newcomers won't have any part of them.
Quote #2
On the fourteenth day of the first month the returned exiles kept the passover. For both the priests and the Levites had purified themselves; all of them were clean. So they killed the passover lamb for all the returned exiles, for their fellow priests, and for themselves. It was eaten by the people of Israel who had returned from exile, and also by all who had joined them and separated themselves from the pollutions of the nations of the land to worship the Lord, the God of Israel. (NRSV Ezra 6:19-21)
And the children of the captivity kept the passover upon the fourteenth day of the first month. For the priests and the Levites were purified together, all of them were pure, and killed the passover for all the children of the captivity, and for their brethren the priests, and for themselves. And the children of Israel, which were come again out of captivity, and all such as had separated themselves unto them from the filthiness of the heathen of the land, to seek the Lord God of Israel, did eat […] (KJV Ezra 6:19-21)
What better way to affirm your religious and cultural identity than with matzah-ball soup? Celebrating Passover is one of the classic ways of rediscovering one's Jewish roots. Ethnic foods have enormous importance in cultural identity, whether it's corned beef and cabbage, buche de noel, lutefisk, or thin-crust pizza vs. deep-dish. Wars have been fought over this kind of stuff.
Quote #3
After these things had been done, the officials approached me and said, "The people of Israel, the priests, and the Levites have not separated themselves from the peoples of the lands with their abominations, from the Canaanites, the Hittites, the Perizzites, the Jebusites, the Ammonites, the Moabites, the Egyptians, and the Amorites. For they have taken some of their daughters as wives for themselves and for their sons. Thus the holy seed has mixed itself with the peoples of the lands, and in this faithlessness the officials and leaders have led the way." When I heard this, I tore my garment and my mantle, and pulled hair from my head and beard, and sat appalled. Then all who trembled at the words of the God of Israel, because of the faithlessness of the returned exiles, gathered around me while I sat appalled until the evening sacrifice. (NRSV Ezra 9:1-4)
Now when these things were done, the princes came to me, saying, The people of Israel, and the priests, and the Levites, have not separated themselves from the people of the lands, doing according to their abominations, even of the Canaanites, the Hittites, the Perizzites, the Jebusites, the Ammonites, the Moabites, the Egyptians, and the Amorites. For they have taken of their daughters for themselves, and for their sons: so that the holy seed have mingled themselves with the people of those lands: yea, the hand of the princes and rulers hath been chief in this trespass. And when I heard this thing, I rent my garment and my mantle, and plucked off the hair of my head and of my beard, and sat down astonished. Then were assembled unto me every one that trembled at the words of the God of Israel, because of the transgression of those that had been carried away; and I sat astonished until the evening sacrifice. (KJV Ezra 9:1-4)
This idea of the "holy seed" is a new one introduced by Ezra: the only real Israelite is a person with two Jewish parents, no exceptions. You can't convert, you can't as a foreigner decide to follow God's laws. You either are or are not kosher by birth and nothing can change that. This wasn't an idea that was adopted by everybody. People willing to accept the God of Israel and follow the commandments were typically welcomed into the community. Even King David, God's anointed, was the grandson of Ruth, a Moabite convert to Judaism. Ezra was upping the ante here in an effort to maintain the ethnic purity of the community (source).