To answer this question, I think we have to consider the unconditional love Jesus has for all mankind, who are living by His Grace. In addition to His Grace, It is also pertinent to realise that Jesus goes a step further to pry into all hearts. At this point we can see from the examples of the grumbling disciples as well as the pharisees, how He is able to read their thoughts and cautions them appropriately.When we move beyond this to consider the faiths of the centurion, the samaritan woman at the well, the proverbial widow and her contribution to blindman Bathtimeus, then it presupposes that the "lowly" in this context does not imply only those who are physically poor but embraces all those who are spiritually derranged. For this reason, Jesus is advising us to go beyond our discriminative human boundaries into other  areas to rope in the spiritually deficient personalities with capabilities of being saved and this depends on this personality's exhibition of faith in Jesus.