Exegesis:

elegon gar ‘for they were saying’: this explains the reason why the chief priests and scribes were looking for a way to arrest and kill Jesus by stealth.

mē en tē heortē ‘not during the feast’: so most commentators and translations. Jeremias, however, argues for the meaning ‘not in the presence of the festal crowd,’ referring to Jn. 7.11 for this meaning of heortē ‘feast,’ and Lk. 22.6 ‘in the absence of the multitude.’ This gives excellent sense to the words and may be the meaning intended.

thorubos (cf. 5.38) ‘uproar,’ ‘tumult’: here not simply a vocal disturbance but a riot (cf. Goodspeed, Moffatt, Manson, The Modern Speech New Testament; Vulgate tumultus).

tou laou (cf. 7.6) ‘of the people,’ ‘of the populace’: the word here is equivalent to ochlos ‘crowd’ more commonly used by Mark. Arndt & Gingrich see here ‘the people’ in contrast to their leaders.

Translation:

Not during the feast must often be expanded so as to include the implied, but not specifically stated elements, e.g. ‘we must not arrest him during the feast’ (or ‘in the presence of the crowd attending the feast’).

Tumult is a ‘riot,’ translatable in some instances as ‘in order that the people do not start to fight us.’

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 .