John Gill Commentary Mark 12:39

"and chief seats in the synagogues, and chief places at feasts:" — Mark 12:39 (ASV)

And the chief seats in the synagogues
Where the rulers of the synagogue, and the elders of the people sat; (See Gill on Matthew 23:6).

And the uppermost rooms at feasts ;
or the first and chief places where they sat, or rather lay along at public entertainment; (See Gill on Matthew 23:6).