Translation: Abu Sahl (@dhikrulas)
Al-Imām Al-Muzanee (one of the foremost students of Al-Imām Ash Shaafee' 'alayhimā rahmatuLlahi) said:
It was said to whom allows ikhtilāf and claims that: If two scholars make ijtihād on an issue and one of them says: 'This is halāl.' And another says: 'This is harām.' (Then he says): Each one of them is right on his ijtihād. (Ask him): Did you utter this based on evidence or analogical deduction? If he says: 'It is based on evidence.' Say to him: 'How could it be based on evidence while Al Qur'aan negates al ikhtilāf?! If he says: It is based on analogical deduction. Say (to him): How could a deduction negate al-khilāf, and it is allowed for you to deduce from matn (the basic) that al-khilāf is allowed?.
This is what an intelligent person will not allow, not to talk of a scholar.
Sifatus salaatin Nabiyy p.62.