Bhagavad Gita Verse 17.21

किंतु जो दान क्लेश पूर्वक तथा प्रत्युपकार के  प्रयोजन से अथवा फल को दृष्टि में रख कर फिर दिया जाता है, वह दान राजस कहा गया है|

However Arjuna, when the gift is given with the expectation of receiving something in return, when it is also given for the sake of receiving future rewards or when the gift is given unwillingly from one person to another, this gift is considered impure and presented by a person of the Rajas nature.