and in hunting as well.
134 – This shows that no one is allowed to speak on any point of sacred knowledge except by means of ijtihad, and the ijtihad required here is like the effort of searching for the House when determining the qiblah, or of finding the proper equivalent in cases of game.
135 – Ijtihad is open only to someone who knows the proofs that bear on the matter—whether an authoritative report from the Book, the Sunnah, or consensus—and who then pursues the ruling by analogy, reasoning from some of what I have just described, just as one seeks out what is hidden from him of the direction of the House or is uncertain about the equivalent for hunted game.
136 – As for anyone who lacks the necessary tools, it is not lawful for him to say anything about sacred knowledge.
137 – A parallel case is that Allah has stipulated uprightness for witnesses; uprightness consists of obedience and sound judgment for testimony. When these traits are outwardly apparent to us, we accept a person’s testimony on the basis of what is manifest, even though he might be concealing the opposite. We have not been charged with uncovering the unseen, so we are not permitted—while lacking sure knowledge that his inner state matches his outward appearance—to accept the testimony of anyone who turns up if the signs of uprightness are missing. This illustrates the same principle that the previous discussion established.
138 – It therefore makes clear that it is impermissible for anyone to speak on matters of knowledge except in the manner we have described.
139 – He asked, “Can you provide an illustration of this from things that ordinary people recognize?”
140 – I replied, “Yes.”
141 – He said, “What is it?”
142 – I said, “Consider a garment whose defects vary, or a slave, or any other merchandise—when a judge needs to assess its value, to whom does he show it?”
143 – He answered, “He shows it only to those who are knowledgeable about it.”
144 – I said, “That is because their condition differs from that of the ignorant: they know its markets…"