My tenant wants to leave; do I have to refund his rent?

I have let out a villa that I own in Dubai. My tenant wishes to return to his home country and terminate the tenancy contract and asked for a refund of the remaining period of the rent. I do not have the funds to pay him in fact I had spend all the rent amount given by him. I informed him that if I can get a new  tenant, I am willing to refund the existing occupant whatever the new tenant pays in respect of the remaining period of the lease - is this fair solution and am I legally obliged to give any refund at all? In the rent agreement there is no such clause saying that the tenant has the right to terminate the tenancy agreement. 

 I would like to clarify to the questioner that as a landlord he is not obliged to refund the value of the rent to the tenant because the contract equally binds both parties and must be abided by until it is completed. Therefore, if the tenant wants to recover the value of the rent and revoke thecontract, he shall search for another tenant to replace him or to solve this problem with the landlord amicably.