“And say, thus says the Lord Yahweh to Jerusalem, Your birth and your nativity is the land of the Canaanite. The Amorite was your father, and your mother was a Hittite.”
‘To Jerusalem.' This word conjures up two thoughts, Jerusalem as a city, which God had chosen as His dwellingplace (Psalms 132:13), and Jerusalem as representing the whole of what was left of Israel. Israel, even the exiles, were often described as ‘Zion' (e.g. Zechariah 2:7). What remained of the land of Israel was not very large, being composed of Jerusalem and its environs, so that Jerusalem could be seen as representing the whole. Indeed it was the heart of Israel, and bore within it the stamp of the whole. So we do not need to choose between whether he has Jerusalem in mind or Israel. The one was represented by the other.
These words are derogatory. Israel prided itself on its ancestry, and the Canaanites were a byword for immorality and sin, which was why God had demanded that they be utterly destroyed. This latter condemnation was also aimed at the Amorites and the Hittites who dwelt in the land (Deuteronomy 7:1-5; Deuteronomy 20:17). All three names could in fact be used as a general designation for the inhabitants of the land. See among others Genesis 10:16; Genesis 15:16; Numbers 13:29; Joshua 1:4; Joshua 5:1; Joshua 7:7; Joshua 24:15; Joshua 24:18; Amos 2:10.
There are a number of points here. One is that neither Jerusalem nor Israel were in fact as racially pure as they thought. They were of mongrel descent. Israel did in fact include Canaanites, Amorites and Hittites in their ancestry, for such would be among the servants of Abraham, Isaac and Jacob, and among the mixed multitude that became a part of Israel at the exodus and at Sinai, and this was added to by intermarriage contrary to God's command (Deuteronomy 7:3). And the suggestion is that this was now coming out in their behaviour.
The second is that they had become like those that they had lived amongst. They had been established in the land of the Canaanites and had aped the Canaanites, Amorites and Hittites in the land, who had ‘fathered' and ‘mothered' them. That was why they were behaving as they were.
The third was that Jerusalem itself was a city of bastard descent, a city of mixed race, and those races evil. In the wider meaning of the terms the Jebusites who dwelt in Jerusalem were Canaanites and Amorites, and were associated with the Amorites and Hittites as dwellers in the mountains (Numbers 13:29), and they lived among the Israelites, no doubt being forced to submit to the covenant with Yahweh after the capture of the city by David.
Thus Israel's professed purity was a farce. There was nothing in their background to make them especially attractive. Anything they had was because of God's goodness to them.