Psalm 41 says a man is blessed when he considers the poor. The Lord will bless him with deliverance from trouble, protection, life, health and a recognition from others that he is blessed.
Jesus said "give to everyone who begs from you" (Luke 6:30) and "…lend, expecting nothing in return and your reward will be great, and you will be sons of the Most High, for he is kind to the ungrateful and the evil. Be merciful, even as your Father is merciful." (Luke 6:35) And, "give and it will be given to you. Good measure, pressed down, shaken together, running over, will be put into your lap. For with the measure you use it will be measured back to you." (Luke 6:38)
Giving to the poor reflects God's merciful character, pleases him and results in blessings to ourselves.