expression, godan verb (-u)
swear to God; cross one's heart
Used to emphasize the truthfulness of a statement, often in the form 神に誓って (I swear to God). The expression is somewhat dramatic and may carry a Western or Christian nuance in Japanese.
See also: 神に誓って
神に誓って、それは本当にあったことだ。
I swear to God, that really happened.
彼
He swore to God that he was innocent.