The oyster is born and fostered in sea. But all the time she looks up for rainy clouds. This double-layered creature refuses to take the bitter sea water. At the same time she dislikes sweet water. Since she starved and toiled in the deep sea, she bore the pearl.
Note: In the above verses Shah advises the seeker to discard worldly things and simultaneously stick to the remembrance of Allah.
O men! Verily you should labour to your Lord a hard labouring; you shall then meet Him. (6, Al-lnshikak).
مردِ خدا بحر بود بیکراں
مردِ خدا بارد وریں سحاب
(Roomi)
The man of Allah is a boundless sea. The man of Allah rains pearls without a cloud.

Oyster produced in the ocean, pins its hope on clouds,
The two shelled one drinks neither salty your sweet water,
it produces pearl, for in deep water, it bears thirst.

Oyster is reared in sea but looks forward to rainy clouds,
The bivalve never drinks brackish water, it has tasted fresh,
It bore pearl because it does not quench its thirst even though deep in water.