Exegesis:

epelathonto (only here in Mark; cf. lanthanō 7.24) ‘they forgot’: the context requires that this aorist be understood as a past perfect, i.e. ‘they had forgotten (when they set out on the crossing).’

kai ei mē hena arton ouch eichon meth’ heautōn en tō ploiō literally ‘and except for one loaf they didn’t have (anything) with them in the boat.’

Translation:

It is frequently necessary to translate they by ‘disciples’ since the immediately preceding ‘they’ must refer to the Pharisees who were left standing there by Jesus.

Had forgotten usually presents no special difficulties, for the concept of forgetting is common enough in all languages. However, some of the idioms used are of interest, e.g. ‘to lose from the heart’ (Tzeltal), ‘to lose from the liver’ (Miskito), and ‘his insides died’ (Laka).

A literal translation may imply a contradiction. This is treated in some instances as ‘forgotten to bring enough bread; they had only one loaf’ or ‘they had forgotten to bring bread, except for the one loaf which they had with them in the boat.’ However, any minor discrepancy in wording is immediately evident in the following clause, which does not essentially contradict the preceding. The meaning is that they had not procured bread especially for the trip, but they happened to have a loaf with them in the boat.

Quoted with permission from Bratcher, Robert G. and Nida, Eugene A. A Handbook on the Gospel of Mark. (UBS Handbook Series). New York: UBS, 1961. For this and other handbooks for translators see here .