What is lo dri ba? I know that it is a Vinayic term but what does it really mean? Is it “enquiry after (or question about) the age” (of a bhikṣu or śrāmaṇera candidate)? The expression dge slong/slong gi lo dri ba seems to suggest this. The instrumental gis or gnyis seems to be a misinterpretation. The Sanskrit is often given as varṣapṛcchā. We also come across dge slong/tshul gi dang po’i lo dri ba and the Sanskrit as varṣāgrapṛcchā. But is the Sanskrit correct? If it is correct, how are we supposed to understand it? It is of course clear that “age” (varṣa: lo) is important in the Vinaya. One cannot ordain someone as a bhikṣu if the candidate is not at least twenty years of age. So determining the age of the candidate prior to the ordination is important. What about the permitted age to be a śrāmaṇera? The śrāmaṇera candidate must be “one who is able to drive away a crow” (bya rog skrod nus pa), that is, usually seven years of age. So there are some Vinaya treatises bearing lo dri ba in their titles. But I would suppose that such treatises deal more than just questions about the ages of the candidates. But why are such works called lo dri ba? I have no idea.
Now there is a Vinayic treatise called the Śrāmaṇeravarṣāgrapṛcchā (dGe tshul gyi dang po’i lo dri ba). I think one such work is attributed to Padmasambhava. And that is why he is called “Lo-dri-mkhan-po,” which is to be understood in the sense of the “author of the Lo dri.” But obviously Jean Naudou (Naudou 1980 [= English translation of Naudou 1968]: 110–111) had no idea what “Lo-dri-mkhan-po” meant and suggested that “Lo-dri” could have been an error for “O-dri” (i.e. for Oḍḍiyāna) and thus suggested to understand “Lo-dri-mkhan-po” in the sense of “Upādhyāya from Oḍḍiyāna.”