A man over ninety is a great comfort to all his elderly neighbors; he is a picket-guard at the extreme outpost; and the young folks of sixty and seventy feel that the enemy must get by him before he can come near their camp.

Oliver Wendell Holmes, Sr. (1809-1894) American poet, essayist, scholar

Article (1867-01), “The Guardian Angel,” ch. 2 “Great Excitement”, Atlantic Monthly, Vol. 19, No. 91
    (Source)

Collected in The Guardian Angel, ch. 2 (1867).