If you see your brother in need, it doesn't matter if you already gave somewhere else. You should be open to the idea of God using you to meet your brother's unexpected need.
Andy Stanley[God] wants you to go home, look at your bucket of seed, and determine in your heart how much you'd like to sow. He wants you to consider thoughtfully your current circumstances, your life, your potential, and your finances. He wants you to involve your family. He wants you to pray about it. And then He wants you to come up with a plan.
Andy Stanley