A poem by Yehudah ha-Levi
When Fortune's shield protects you, then beware —
Tomorrow, for your foot she sets a snare.
Her gift, an eaglet's pinion — now your flight,
Anon, the lethal arrow — to upbear!
Based on the translation by Solomon Solis-Cohen that's reproduced on page 377 of A Treasury of Jewish Poetry: From Biblical Times to the Present, edited by Nathan and Marynn Ausubel (Crown Publishers, 1957).