The poor have a treasure to offer precisely because they cannot return our favours. By not paying us for what we have done for them, they call us to inner freedom, selflessness, generosity, and true care. Jesus says: « When you have a party, invite the poor, the crippled, the lame, the blind; then you will be blessed, for they have no means to repay you and so you will be repaid when the upright rise again » (Luke 14:13-14).
The repayment Jesus speaks about is spiritual. It is the joy, peace, and love of God that we so much desire. This is what the poor give us, not only in the afterlife but already here and now.