Job 7:2 Kabbalah

כְּעֶ֥בֶד יִשְׁאַף־צֵ֑ל וּ֝כְשָׂכִ֗יר יְקַוֶּ֥ה פָעֳלֽוֹ׃

As a servant that eagerly longeth for the shadow, And as a hireling that looketh for his wages;

Read kabbalistic (mystical) interpretation of Job 7:2: and classical mystical sources.