Proverbs 3:28 Say not unto thy neighbour, Go, and come again, and to morrow I will give; when thou hast it by thee.
When others request our aid we should do our utmost to provide and be there for them within our ability. This is an integral piece of loving our neighbours as ourselves, and can be difficult. Suppose that whatever your neighbour is asking for is meant to provide for you, or your own family; like Elijah asking the widow for her last meal;
1 Kings 17:9-12 Arise, get thee to Zarephath, which belongeth to Zidon, and dwell there: behold, I have commanded a widow woman there to sustain thee. So he arose and went to Zarephath. And when he came to the gate of the city, behold, the widow woman was there gathering of sticks: and he called to her, and said, Fetch me, I pray thee, a little water in a vessel, that I may drink. And as she was going to fetch it, he called to her, and said, Bring me, I pray thee, a morsel of bread in thine hand. And she said, As the LORD thy God liveth, I have not a cake, but an handful of meal in a barrel, and a little oil in a cruse: and, behold, I am gathering two sticks, that I may go in and dress it for me and my son, that we may eat it, and die.
By faith, the widow prepares a meal for him, and her family is taken care of for as long as was needed after that through the miraculous power of God. Trust in God to provide for you, and trust Him when He chooses to provide through you.
