The paper contains an attempt to reinterpret the motto and clarify the date of the lead pendant seal of Grand Duke of Moscow, Dmitry Donskoy (1363-1389). Among numerous princely pendant seals of 14th-15th cent., th? seal under discussion is known as a unique one due to inscription and image of the obverse. Unlike other seals, with images of patron saints of the princes - owners, the seal of Dmitry Donskoy is decorated with the head of a king encircled with the motto Everything Passes. The reign of Grand Duke Dmitry Donskoy fell on time of pan-European pandemic of plague, that came to Rus' in 1353. Comforting tone of motto was dictated by a heavy moral atmosphere caused by plague, that seriously impacted the Moscow Grand Duke's House. The idea of the original decoration of the seal probably belonged to Metropolitan of Moscow Alexei (between 1292 and 1305-1378).