What is the ruling on restricting fatwas to only the four schools of thought, and to whom were the sayings of the imams, "Do not imitate me, nor imitate Malik," directed?

The preponderant opinion is that it is permissible to follow any of the four Imams, as well as others whose madhhab (school of thought) has been preserved, codified, and whose conditions and other considerations are known.

Some scholars have held that it is not permissible to depart from the four madhahib, neither in practice, nor in fatwa (religious edict), nor in judicial ruling. Some of them even transmitted a consensus (ijma') on the obligation of following the four madhahib, but this consensus is not accepted as valid.