How can the Lord say to Balak (through Balaam) that He saw no iniquity in Jacob when time and again he gets angry at their rebellion?
It is an interesting question, but one, I think, that is easily answered. Israel, as a nation, was blessed. The only one who can curse is the same one who blessed – in this case, God. No matter prophet is asked, no matter how “saintly” he may be, he can only do that which the Lord allows, and the Lord was not going to allow Israel to be cursed by a people whose interest was harm to God’s chosen.
This encourages us to note that what the Lord blessed (protects), no man or superhuman power can undo (cf. John 10:28-29). It was not a matter of there being no sin in Israel for it is abundantly clear that there was; it was a matter, however, that when the Lord is on the side of one (or many), He will “air” no dirty laundry, but to those who need washing.
Here is an illustration that most accept: my wife can look at me and note the many failures in my life as a husband, but only she can speak about them – she will let no one else speak of them; this is her love protecting me (and I need a lot a protection!).