This is again an unreasonable standard and those listening recognized it as such.
Jesus was setting an impossible standard so that the hearers would recognize their need for a Saviour.
We are inundated with homeless people asking for handouts. Most of these people are professional pan-handlers many of which use the money for drugs and alcohol.
We ought to be sensitive to the HolySpirit who will enable us to get a reading on the person. Furthermore, our gifts should at least purchase an opportunity for us to minister to the recipient the Gospel of Jesus Christ.