Kierkegaard, Christian Discourses
IV, 2 (on Matthew 11.28, tr. Walter Lowrie):
'All they that labour and are heavy laden', all of them, none is excepted, not one. Ah, what manifold diversities are suggested by these words. They that labour! For not only that man labours who in the sweat of his brow labours for his daily bread, nor he only who in lowly station bears the burden and heat of the day; ah, he also labours who struggles with sad thoughts, he too labours who is concerned by the care of one or many, he too labours who contends with doubt, labouring in that sea as a swimmer is said to labour. They that are heavy laden! For not only is that man heavy laden who visibly bears the heavy burden, who is visibly situated in difficulties, but he too is heavy laden whose burden no one has seen, who perhaps even labours to hide it; and not only is he heavy laden before whom there lies a life of trial saddened by recollection, but he too for whom, alas, there seems to be no future.