Sheikh `Iyâd b. Nâmî al-Sulamî
A general text becomes ambiguous when it is specified by another text that specifies it, makes an exception to it, or otherwise narrows its scope in an ambiguous manner. A verse is ambiguous when it requires further evidence to clarify it.
An example of this situation is the verse: "All cattle are lawful to you except what is pronounced to you as unlawful." [Sûrah al-Mâ'idah: 1]
Here we have a general ruling "all cattle are lawful to you".
We also have an exception being made to this general ruling, but that exception is vague and ambiguous. Its extent and specifics are unknown. This is the statement: "except what is pronounced to you as unlawful."
This exception needs to be clarified by other evidence. When the Prophet's Companions first heard this verse, they had no way of knowing which, if any, types of cattle were going to be prohibited to them as food. The ruling of the verse remained ambiguous until Allah clarified in other verses what the prohibited cattle were.
Scholars differ regarding the general ruling propounded by such verses before the ambiguity is lifted.
The majority of scholars are of the opinion that the general ruling is not to be acted upon, and that the whole issue remains ambiguous until the matter is clarified by other evidence.
Some scholars of the Hanafî school of law disagree. They hold the view that the general ruling remains in full effect until the ambiguity is lifted. They argue that since the exception being made to the general ruling is unclear, that exception has no effect upon the general ruling until it is clarified.
Consider our example: "All cattle are lawful to you except what is pronounced to you as unlawful." [Sûrah al-Mâ'idah: 1]
According to the majority of jurists, this verse cannot be acted upon at all until the exception is clarified. According to al-Sarakhsî and other Hanafî jurists, this verse remains proof that all cattle are lawful as food animals, and this general ruling of permissibility remained in effect for the Comoanions until other evidence clarified for them what the exceptions to that general permissibility were – for instance pork and carrion.
And Allah knows best.
Source: Islam Today