Is it obligatory to teach the ignorant person the Sharia ruling even if he does not ask, and when is that obligatory?

Scholars have differed on whether it is obligatory to teach an ignorant person before they ask, or merely obligatory to alert them, and then teach them if they ask. Some believe that teaching is obligatory upon encountering an ignorant person, citing the hadith of the Bedouin who urinated in the mosque. Others hold that the hadith of the Bedouin who did not pray properly indicates that teaching is not obligatory unless a question is asked. The correct view is that teaching the ignorant is legislatively required, and it is part of conveying knowledge, which is a communal obligation (fard kifayah). Therefore, if there is no one to teach them, and their knowledge is among the obligations, then teaching them becomes individually obligatory even if they do not ask. However, if there are enough people to suffice for teaching, or if the knowledge is not obligatory, then teaching is not individually obligatory before a question is asked.