Time-servers are the cowering slaves of slaves,
Alone on earth, who serves the Lord is free,
Each soul shall win the gift that it most craves;
Seek God, my soul -- God shall your portion be!
Based on the translation by Solomon Solis-Cohen that's reproduced on pages 376-377 of A Treasury of Jewish Poetry: From Biblical Times to the Present, edited by Nathan and Marynn Ausubel (Crown Publishers, 1957).
Yehudah HaLevi
http://www.poemhunter.com/poem/time-servers/
