A very famous allegory used by Adi Shankaracharya is that he says my worship is like water worshipping to the ocean. Where is it found?
One of the many wonderful compositions of Adi Shankaracharya is the Soundarya Lahari (Waves of Beauty). This poem worships Shakti, the feminine form of the Divine. At the end of Soundarya Lahari, Adi Shankara says:
Oh Goddess who is the source of all words,
This poem which is made of words,
That you only made,
Is like showing the camphor lamp to the Sun,
Is like offering as ablation to the moon,
The water got from the moon stone,
And is like offering water worship,
To the sea.