BT BM 42b(7) :משתבע איהו דהנהו זוזי אשלמינהו לאימיה ומשתבעא אימיה דהנהו זוזי אותבינהו בקרטל׳ ואיגנוב‏ : he swears that he gave that money to his mother, and his mother swears that she placed that money in a small basket, and it was stolen
See the entire entry for šbˁ vb. C to swear