ἴσχον

From LSJ

λύπης ἰατρός ἐστιν ὁ χρηστὸς φίλος → a true friend is grief's physician, a worthy friend is a physician to your pain

Source

Russian (Dvoretsky)

ἴσχον: τό [part. sing. n к ἴσχω помеха, препятствие, задержка (τὸ ἴ. τῆς ῥοῆς Plat.; τὸ ἴ. τὴν πορείαν Xen.).