1,759. Invalidating a Get
Hilchos Geirushin 6:21
If a man sends a get with an agent and he subsequently cancels it, he may later divorce his wife with it at any time. He didn’t cancel the validity of the get, he canceled the agent’s assignment. Therefore, if a get is in a husband’s possession and he cancels it by declaring it void, then he can never use it for purposes of divorce. It’s like broken pottery and if used for a divorce, divorce is not effected. Similarly, if a get was given to an agent but the husband explicitly states that the get he sent is nullified from its use as a get, then it may never be used for purposes of divorce.
Hilchos Geirushin 6:22
Phrases that can invalidate a get include, “it is voided,” “I can’t follow it,” “let this get be invalidated,” “let it not permit,” “let it not release,” “let it not send out,” “let it not divorce,” “let it be a shard,” “let it be like a shard,” and “it is like a shard.” These and similar expressions can invalidate a get.