Indian Evidence Act, 1872
94. Exclusion of evidence against application of document to existing facts
When language used in a document is plain in itself, and when it applies accurately to existing facts, evidence may not be given to show that it was not meant to apply to such facts.
A sells to B, by deed, "my estate at Rampur containing 100 bighas". A has an estate at Rampur containing 100 bighas. Evidence may not be given of the fact that the estate meant to be sold was one situated at a different place and of a different size.