Interesting comment on interpreting potentially ambiguous expressions in written documents:

In the first place it should be shown, if possible, that there is no ambiguity in the statement, because in ordinary conversation everyone is accustomed to use this single word or phrase in the sense in which the speaker will prove that it should be taken. In the second place it must be shown that from what precedes or follows in the document the doubtful point becomes plain. Therefore if words are to be considered separately by themselves, every word, or at least many words, would seem ambiguous; but it is not right to regard as ambiguous what becomes plain on consideration of the whole context. In the next place, one ought to estimate what the writer meant from his other writings, acts, words, disposition and in fact his whole life, and to examine the whole document which contains the ambiguity in question in all its parts, to see if any thing is apposite to our interpretation or opposed to the sense in which our opponent understands it. For it is easy to estimate what it is likely that the writer intended from the complete context and from the character of the writer, and from the qualities which are associated with certain characters. Cicero, De Inventione, II.116-117 (ET: H.M. Hubbell, Loeb, 1949).

Very sensible advice for the interpretation of written texts: ordinary usage, documentary context, authorial setting. I am interested in this last aspect especially, that the interpretation of a text (or a difficulty in a text) ought to take account of "what the writer meant from his other writings, acts, words, disposition and in fact his whole life", since this is precisely what a letter carrier could contribute to the reception and interpretation of a Pauline letter (cf. esp. Col 4.7-9).