Merry Christmas! Here’s a snippet of ancient life that appealed to me this morning.
Antigonus the elder communicated to his son Demetrius his intention to put Mithridates to death, but bound him by a solemn oath “not to speak of it.” Demetrius took Mithridates a walk by the seaside, and wrote on the sand with the end of his spear, “Run.” Mithridates took the hint, and escaped to Pontus, where he afterwards became king.
— Plutarch, Apophthegms, or Sayings of Kings and Commanders: Antigonus, 18.
I find that there is a version of this complete text online here. Of a similar kind is the Sayings of the Romans here.