Не болтай!

Не болтай! будь на чеку в такие дни подслушивают стены недалеко от болтовни и сплетни до измены.

do not chat!

watch your back on such days eavesdrop on the walls not far from chatter and gossip before treason.

(kind of shows how AI translators still have a way to go...)We saw this during one of our walks around Moscow (the one in Idaho).