Job 10:13 - Ellicott's Commentary On The Whole Bible

These things hast thou hid in thine heart. — Job implies that his sense of God’s goodness is embittered by the thought that while showing him such kindness, He had in reserve for him the trials and sorrows under which he was then labouring: while showering good upon him, He intended eventually to overwhelm him with affliction. This was the purpose He had hidden in His heart.