Not judging others is an act of mercy. It is a reflection of what God has done for us. Jesus did not say specifically what we are to give, but he is describing God's gift of grace to us, and his words clearly indicate that our giving should be in abundance, just as God has given to us.
"A good measure, pressed down, shaken together, and running over." This language reflects the interaction between a merchant and his customer. The merchant wants to honor the customer. After he fills the required measure he adds more wheat, pressed down, abundant. He then shakes the measure until the wheat runs over, and then he fills it again. The merchant then adds more wheat so that the wheat again overflows, and the customer joyfully receives the abundance into his lap.
"Remember that the person who plants few seeds will have a small crop; the one who plants many seeds will have a large crop. You should each give, then, as you have decided, not with regret or out of a sense of duty; for God loves the one who gives gladly. And God is able to give you more than you need, so that you will always have all you need for yourselves and more than enough for every good cause." (2 Corinthians 9:6-8)
If we forgive people, have mercy on them, and stop judging them, God will have mercy on us and forgive our sins. At times God chooses to give to us in proportion to how we give to others.
John Chrysostom said, "If mercy leads us to hold firm to our merciful God and if we ask for his mercy, we need to show mercy to our brothers instead of judging them."
God, you said we should forgive and we will be forgiven. You are the fountain of all forgiveness and mercy. Fill our hearts and make them overflow with the abundance of your mercy and forgiveness. May this challenge our souls and may we follow your example and forgive others in the same manner as you have done on the cross.