The third category is of the person who has heard the...
The third category is of the person who has heard the Prophet ordering something to be done, but the Prophet later on forbade the same. The man knows the former but is unaware of the latter. Or the man has heard the Prophet forbidding something but afterwards the Prophet has made it permissible. The man knows the former, but does not know the latter. Thus the man was in the know of the abrogated (as-Sunnah), but was not aware of its abrogative.
If he had been aware that it has been abrogated he himself would have withdrawn his own narrated tradition. If the Muslims had been in the know that the Prophet had cancelled what the man had related (in the authority of the Prophet) they would have themselves rejected his version. The fourth and the last is the category of the person who had never attributed false statements to the Prophet and who hated false statements because of his fear of Allah and reverence for the Prophet.
He never forgets anything from what he had heard from the Prophet. He always relates exactly what he had heard from the Prophet without adding anything to or subtracting anything from it. He is in the know of both what supersedes and also what has been superseded. Hence he acts according to what supersedes, leaving aside the superseded.
Verily, the commands of the Prophet are also like the verses of he quran which consist of the superseded and the superseding (general and the specific) precise (muhkam) and the ambiguous and multi meaning (mutashabih). Like the quran, the Prophet's wordings also had two aspects, that is, the general and the specific.
As Almighty Allah Himself has said, ?And whatever the Apostle gives you, you accept it, and from whatever he prevents, you be away (from it).' (al-Hashr 59:7) Thus the one who was not aware of all these (complications) would fall in doubt and would not understand what Allah and His messenger exactly meant. It was not at all a fact that all the companions of the prophet had the ability of either asking the Prophet a question or of understanding his answers.
There were some who used t put question to the Prophet but could not understand his answer. There were also others who did ask the Holy Prophet a question but did not understand his answer until they did like some Bedouins or a wayfarer to come and ask the Prophet some questions so that they could have a chance to be enlightened by the Prophet's answer.