What was to happen during the 70th week?:
“Messiah shall be cut off.” The Hebrew word translated “cut off” here (karath) “is used of the death penalty, Lev. 7:20; and refers to a violent death,” i.e, the death of Christ on the cross.
… Negatively, Messiah’s cutting off in verse 26 results from Israel’s completing her transgression and bringing it to a culmination (v 24) by crucifying the Messiah….Considered from its positive effect, this confirming the covenant with many makes reconciliation and brings in everlasting righteousness (v 24).