A.T. Robertson Commentary Luke 12:25

"And which of you by being anxious can add a cubit unto the measure of his life?" — Luke 12:25 (ASV)

A cubit (πηχυν). Matthew 6:27 has πηχυν ενα (one cubit, though ενα is sometimes merely the indefinite article.

Stature (ηλικιαν) as in Matthew, which see.