“But strive still to be a man before your mother.”

The Prophet said, "Your father."
Sahih al-Bukhari, 8:2
Sunni Hadith

1940s, Fourth Inaugural Address (1945)
Context: We shall strive for perfection. We shall not achieve it immediately — but we still shall strive. We may make mistakes — but they must never be mistakes which result from faintness of heart or abandonment of moral principle.

"Preparation," trans. Czesław Miłosz and Robert Hass
Unattainable Earth (1986)
Context: I still think too much about the mothers
And ask what is man born of woman.
He curls himself up and protects his head
While he is kicked by heavy boots; on fire and running,
He burns with bright flame; a bulldozer sweeps him into a clay pit.
Her child. Embracing a teddy bear. Conceived in ecstasy.

The Three Graves
Bartlett's Familiar Quotations, 10th ed. (1919)

Ὅτι οὐδὲν ἧττον τὰ αὐτὰ ποιήσουσι, κἂν σὺ διαρραγῇς.
VIII, 4
Source: Meditations (c. 121–180 AD), Book VIII

Things to Come (1936)

2009, Nobel Prize acceptance speech (December 2009)
Context: We can acknowledge that oppression will always be with us, and still strive for justice. We can admit the intractability of deprivation, and still strive for dignity. Clear-eyed, we can understand that there will be war, and still strive for peace. We can do that — for that is the story of human progress; that's the hope of all the world; and at this moment of challenge, that must be our work here on Earth.

Es irrt der Mensch, so lang er strebt.
Variant translation: Man will err while yet he strives.
Prologue in Heaven
Faust, Part 1 (1808)

<span lang="he" dir="rtl">במקום שאין אנשים, השתדל להיות איש.</span>
Bemakom she'ein anashim, hishtadel lihyot ish.
2:6
Pirkei Avot