Smile on this
My bold endeavour.

[Audacibus annue coeptis]

Virgil (70-19 BC) Roman poet [b. Publius Vergilius Maro; also Vergil]

Georgics [Georgica], Book 1, l. 40ff (1.40) (29 BC) [tr. Rhoades (1881)]
    (Source)

Calling on (now declared divine) Augustus Caesar to bless his poetry. This line, and a similar one in Virgil's Aeneid (9.625), inspired the phrase "Annuit cœptis" ("He [God] has favored our undertakings") on the reverse of the Great Seal of the United States.

(Source (Latin)). Alternate translations:

Aid my bold design.
[tr. Ogilby (1649)]

To my bold Endeavours add thy Force.
[tr. Dryden (1709), l. 60]

Aid my bold design.
[tr. Nevile (1767), l. 50]

Favour my adventurous enterprise.
[tr. Davidson (1854)]

Bid my gallant enterprise succeed.
[tr. Blackmore (1871)]

Favor my bold emprise.
[tr. Wilkins (1873)]

Our bold endeavor bless.
[tr. King (1882)]

Favor my adventurous enterprise.
[tr. Bryce (1897)]

Favour my bold endeavour.
[tr. Mackail (1899)]

Smile on this
My bold endeavour.
[tr. Greenough (1900)]

O smile upon this my bold emprise!
[tr. Way (1912)]

Give assent to my bold emprise.
[tr. Fairclough (Loeb) (1916)]

Be gracious to this my bold design.
[tr. Day-Lewis (1940)]

Condone this enterprise
Of bold experiment.
[tr. Bovie (1956)]

I hope for an easy passage in this bold venture.
[tr. Slavitt (1971)]

Assent to bold undertakings.
[tr. Miles (1980)]

Smile on my enterprise.
[tr. Wilkinson (1982)]

Agree to my bold beginning.
[tr. Kline (2001)]

Assent to this work boldly begun.
[tr. Lembke (2004)]

Bless the boldness of this undertaking.
[tr. Fallon (2006)]

Approve my bold endeavour.
[tr. Johnson (2009)]

Grant me the right to enter upon this bold
Adventure of mine.
[tr. Ferry (2015)]

Look with favor upon a bold beginning.
[Bartlett's]