To go out boldly to face a challenge or begin an undertaking; used in literary, historical, or humorous contexts.
"Armed with a shopping list and an umbrella, she sallied forth into the Saturday market crowds."
Once more unto the breach, dear friends, once more.
— William Shakespeare, Henry V, Act III, Scene 1 (c. 1599) — captures the same spirit of sallying forth though the exact phrase differs