Why was Israel in captivity?
Israel was in captivity because of their rebellion and sinfulness. They had sinned, committed iniquity, done wickedly, and rebelled by departing from God's precepts and judgments. Daniel confessed this on behalf of his people, acknowledging the nation's disobedience as the reason for their captivity.
Les explains that Daniel was a young Jew in captivity, out of his homeland, clear out in a pagan land, strange and far from home. In chapter 9, Daniel prays on behalf of his people Israel. He confesses, 'We have sinned, we have committed iniquity, we have done wickedly, and we've rebelled, even by departing from thy precepts and from thy judgments.' Les points out that this is exactly why they were in captivity—because of their rebellion and sinfulness. Daniel includes himself with the nation, identifying with their disobedience as he intercedes.
We have sinned, and have committed iniquity, and have done wickedly, and have rebelled, even by departing from thy precepts and from thy judgments: