When is a young person permitted to exercise ijtihad and issue fatwas?

Exercising independent reasoning (ijtihad) in matters of religious law has conditions. It is not for every individual to issue a fatwa unless they possess knowledge, qualification, and the ability to discern valid and weak evidence, abrograting and abrogated texts, specific and general rulings, absolute and restricted meanings, and concise and elaborated expressions. It also requires extensive practice and knowledge of the branches of jurisprudence and the opinions of scholars, as well as memorizing or understanding the sacred texts. Taking it upon oneself to issue a fatwa without qualification is a grave sin and speaking without knowledge. Allah the Almighty says: "And do not say about what your tongues falsely describe, 'This is lawful and this is unlawful,' to invent a lie against Allah. Indeed, those who invent a lie against Allah will not succeed." And in the Hadith: "Whoever issues a fatwa without sound basis, its sin is upon the one who issued it." A student of knowledge should not rush into issuing a fatwa, but should know the source of their statement, its evidence, and who has stated it before them. If they are not qualified, they should leave the matter to those who are, and continue learning until they become qualified for ijtihad.