The World Federation One Stop Fiqh

Ruling 12

If for a period of time a mukallaf performs his actions without following a mujtahid, there are two situations to consider: the first is that his actions were in actual fact correctly performed, or they happened to be in accordance with the fatwa of a mujtahid who at present could be his marjaʿ;8 in this case, his actions are valid (ṣaḥīḥ). The second is that he was inculpably ignorant (al‐jāhil al‐qāṣir),9 and his defective actions were not elemental actions (arkān)10 and suchlike; in this case as well, his actions are valid.
Similarly, [one’s actions are deemed to be valid] if he was culpably ignorant (al‐jāhil al‐muqaṣṣir)11 and his defective actions were of the type that if performed unknowingly they are valid, such as reciting [Sūrat al-Ḥamd and the second surah in prayers] aloud (jahr) instead of reciting them in a whisper (ikhfāt), or vice versa.12 Similarly, if a person does not know how he performed his actions, they are deemed to have been performed correctly, apart from a few cases that are mentioned in Minhāj.13

8 A marjaʿ is a jurist who has the necessary qualifications to be followed in matters of Islamic jurisprudence (fiqh). See Ruling 2.
9 ‘Inculpably ignorant’ (al‐jāhil al‐qāṣir) is a term used to refer to someone who has a valid excuse for not knowing; for example, he relied upon something that he thought was authoritative but in fact was not.
10 Arkān is plural of rukn and refers to the elemental components of ritual acts of worship. There are specific rules that govern the validity of ritual acts of worship if a rukn is omitted or added. For example, with regard to prayers, the omission of a rukn renders the prayer invalid (bāṭil). See Ruling 928.
11 ‘Culpably ignorant’ (al‐jāhil al‐muqaṣṣir) is a term used to refer to someone who does not have a valid excuse for not knowing; for example, he was careless in learning religious laws
12 See Ruling 981.
13 This is a reference to Minhāj al‐Ṣāliḥīn, al-Sayyid al-Sistani’s more detailed work on Islamic law.