Beautiful lyrics by Javed Akhtar, soulful rendition by Sonu Nigam and Madhushree and soul-rendering music by AR Rehman! You can catch a glimpse of the song here:

The lyrics are:

In lamhon ke daaman mein
Pakeeza se rishte hain
Koi kalma mohabat ka
Dohrate farishte hain

Khamosh si hai zameeen hairaan sa falak hai
Ek noor hi noor sa abb aasmaan talak hai

Nagmein hi nagmein hai jagti soti fizaon mein
Husn hai sari adaon mein, Ishq hai jaise hawaon mein

Nagmein hi nagmein hai jagti soti fizaon mein
Husn hai sari adaon mein, Ishq hai jaise hawaon mein

Kaise yeh ishq hai
Kaisa yeh khwaab hai
Kaise jazbaat ka Umda sailab hai

Kaise yeh ishq hai
Kaisa yeh khwaab hai
Kaise jazbaat ka Umda sailab hai

Din badle raatein badli
Jeene ke andaaz hi badle hain

In lamhon ke daaman mein
Pakeeza se rishte hain
Koi kalma mohabat ka
Dohrate farishte hain

Samay ne yeh kya kiya
Badal di hai kaya
Tumhein mene paa liye
Mujhe tumne paya

Mile dekho aise hai hum
ke do sur ho jaise madham
koi jyada na koi kaam
Kise aag mein Ke prem aag mein
Jalte dono hi the tan bhi maan bhi
Maan bhi hai tan bhi

Mere khwaabon ke is Gulistaan mein
Tumse hi tum bahar chai hai
Phoolon mein rang nahi the lekin
Dil mein khusboon tumhi se aai hai

Kyon hai yeh arzoo
Kyon hai yeh zustzu
Kyon dil bechain hai
Kyon dil betaab hai

Din badle raatein badli baatien badli
Jeene ke andaaz hi badle hain

In lamhon ke daaman mein
Pakeeza se rishte hain
Koi kalma mohabat ka
Dohrate farishte hain

Nagmein hi nagmein hai jagti soti fizaon mein
Husn hai sari adaon mein
Ishq hai jaise hawaon mein