ο φίλος τον φίλον εν πόνοις και κινδύνοις ου λείπει → a friend does not abandon his friend in difficulties and in danger, a friend in need is a friend indeed
subs.
Ar. and V. ψήκτρα, ἡ, Ar. and P. στλεγγίς, ἡ (Plat.), στελγίς, στελεγγίς, τλεγγίς.