This sher is famous in the the name of Bahadur Shah Zafar but its actually written by Seemab Akbarabadi. Seemab wrote the complete ghazal in a mushaira at Aligarh in 1919.
ye ishq nahīñ āsāñ itnā hī samajh liije
ik aag kā dariyā hai aur Duub ke jaanā hai