Is it permissible for one who is not a scholar to engage in ijtihad regarding matters of fiqh and thereby earn reward?

Ijtihad (independent reasoning) in deriving legal rulings is permissible only for those qualified and in its proper place, as Allah Almighty says: "And when there comes to them information about [public] security or fear, they spread it. But if they had referred it to the Messenger or to those in authority among them, then the ones who [can] draw correct conclusions from it would have known it" (An-Nisa: 83). So, whoever is among those qualified for istinbat (deriving conclusions) will be rewarded, and whoever is not will bear sin and burden, because that is speaking about Allah without knowledge, and it is one of the gravest major sins, as Allah Almighty says: "Say, 'My Lord has only forbidden immoralities - what is apparent of them and what is concealed - and sin, and oppression without right, and that you associate with Allah that for which He has not sent down authority, and that you speak about Allah that which you do not know'" (Al-A'raf: 33). Therefore, only scholars should engage in ijtihad, and on condition that they reach its rank, which requires exerting effort in considering the intent of the Sharia, understanding and memorizing what is established from the Book and the Sunnah, knowing the abrogating and abrogated verses, and having knowledge of the principles and branches of Islamic law, and the Arabic language.