Cause resemble the result and the result must resemble the cause. People who have looked down, abuse and belittle others will create causes towards taking rebirth in such situations where we are beggars on the street. There are many teachings on karma but none are as potent as the Wheel of Sharp Weapons by Dharmarakshita on this matter and for such wretched conditions, there are 4 stanzas that correspond to the conditions of living on the street. Check it out:-
(13) When we lack any freedom, but must obey others,
This is the wheel of sharp weapons returning
Full circle upon us from wrongs we have done.
Till now we have looked down upon them who were lowly
And used them as servants for our own selfish needs;
Hereafter let's offer our service to others
With humble devotion of body and life.
(14) When we hear only language that is foul and abusive,
This is the wheel of sharp weapons returning
Full circle upon us from wrongs we have done.
Till now we have said many things without thinking;
We have slandered and caused many friendships to and.
Hereafter let's censure all thoughtless remarks.
(15) When we are born in oppressive and wretched condition,
This is the wheel of sharp weapons returning
Full circle upon us from wrongs we have done.
Till now we have always had a negative outlook
We have criticized others, seeing only their flaws
Hereafter let's cultivate positive feelings
And view our surroundings as stainless and pure.
(16) When we are parted from friends and from those who can help us,
This is the wheel of sharp weapons returning
Full circle upon us from wrongs we have done.
Till now we have taken the friends and good servants
Of others away, wanting them for ourselves;
Hereafter let's never cause close friends to part.