It is trite law that oral evidence is inadmissible to contradict the contents of a document. In other words oral testimony cannot be used to state the content of a document. This is so, because documents when tendered and admitted in court are like words uttered and do speak for themselves. They are more reliable and authentic then words from the vocal cord of man as they are neither transient nor subject to distortion and miss-interpretation but remain permanent and indelible through the ages.
– Muntaka- coomassie, JSC. Ogundele v. Agiri (2009) – SC