What is the rule regarding testimony concerning a statement (Qawl)?

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The ruling regarding testimony upon a statement is the same as the ruling concerning a sale (Bay'), except for marriage (Nikah), which is treated as a single act. If one witness testifies that a marriage occurred yesterday, and another testifies it occurred today, the testimony is not complete according to all scholars. This is because the marriage of yesterday is distinct from the marriage of today, meaning only one witness testifies to each specific contract, thus it is not established, similar to when testimony concerns an act.