The theme of the poem 'Divination by a Daffodil' by Robert Herrick is the ability to guess something, perceive something through intuition or prescience. In the case of Robert Herrick, his premonition is of his own death, and he is sparked to think of it by the sight of a daffodil as it blooms, withers and dies. Many people, such as William Wordsworth have been moved to glorious feelings of joy by the sight of daffodils, but Herrick is more preocccupied with their withering than their blooming. In this neat, careful economical little poem he describes the stages 'first I will decline my head.' He envisages old age and frailty, and by intuition can sense (helped by the image of the dying flower in front of him) the way that all this life will play out towards its end. In this, he he 'divines' or senses his, and our, future under the earth.
The theme of this poem is the transience of human life -- the idea that human life is brief and fleeting. In other words, its theme is the idea that we are all going to die. Like many other poems, this one makes this point by comparing human life with things from nature.
The word "divination" (as any Harry Potter fan should know) means fortune telling. In the poem, the speaker is saying that seeing a daffodil helps him tell his own future. He knows that he, like the daffodil, will end up wilting and dying.
The theme of Robert Herrick's (1591-1674) "Divination by a Daffodil" is that all human life like everything else in Nature is temporary and will end in death.
The poet looks at a daffodil which has withered - hanging down his head towards me- and he realizes that the same fate awaits him sooner or later. No matter how beautiful the daffodil may be, at the end of the day it will wither and die. Similarly, Robert Herrick realizes that no matter how much he may achieve during his life time he will also have to die like the daffodil.
The sight of the withered daffodil, 'divines' or foretells his death and his burial.