
Here are some Buddha Koans that can be used in your meditation, extracted from the "Pointing at the Moon Records":
1. One day the Buddha sat on the high seat getting ready to expound the Dhamma. So Ven Maha Kassapa knocked the pestle on the ground and declared: "The World-honoured One has finished his sermon!" At this the Buddha got up and left.
For this Koan, meditate on "when did the Buddha give a sermon?"
2. Once the Buddha took a colour changing Mani Jewel and asked the 5 Celestial Kings: "What colour is this jewel?" Each King saw a different colour and responded accordingly. The Buddha then hid the jewel and asked them the same question with an empty hand. The Kings replied: "There's no jewel in your hand, Lord, so how can there be any colours?" The Buddha said: "How deluded you all are. Earlier I showed you a worldly jewel and each of you told me of a different colour. Now I am showing you the true jewel, yet you do not know it!" At that moment, the 5 Celestial Kings all attained enlightenment.
For this Koan, meditate on "what is the true jewel?"
3. At one time the Brahmin Kala made an offering of flowers to the Buddha. The Buddha responded by saying: "Rishi (hermit), let it go!" The Brahmin put down the flower in his left hand. The Buddha repeated again: "Rishi, let it go!" The Brahmin put down the flower in his right hand. The Buddha repeated himself for the 3rd time: "Rishi, let it go!" And the Brahmin said: "Both my hands are empty, what else will you have me put down?" Finally the Buddha told him: "I did not teach you to let go of the flowers. What you should let go are the external 6 sense objects, the internal 6 sense organs and the 6 sensory awareness in between. When everything is let go, until there is nothing left to let go, that is where you can find your true self." The Brahmin realized the Unborn Dhamma upon hearing these words.
For this Koan, meditate on "what is left when there is nothing left to let go?"
4.There was a Rishi who have attained the 5 supernormal powers (Clairvoyance, Clairaudience, Telepathy, Recollection of past-lives & Mind-body projection) asking the Buddha: "World-honoured One, you possess the 6 supernormal powers, whereas I only have 5 powers. What is the 6th power?" The Buddha suddenly exclaimed: "Rishi!" The Rishi answered: "Yes, lord?" Buddha: "That power; why do you ask me?"
For this Koan, meditate on "what is the 6th power?"
5. The Buddha was travelling with the Ven Ananda when they passed by the stupa of a past Buddha. The Buddha prostrated before the stupa, and Ven Ananda asked him: "Who does this stupa belong to?" Buddha: "It belongs to one of the past Buddhas." Ananda: "The past Buddhas were whose disciples?" Buddha: "They were my disciples." Ananda: "That should be the case."
For this Koan, meditate on "who is the Buddha?"
By meditating, it does not mean that you have to sit down all the time, but constantly contemplate on the answer to any of these Koans no matter whether you are sitting, walking, standing or lying down. When the time is ripe, this one thought of fluctuating ignorance will break through your fundamental ignorance and allow you the see your true Buddha-nature. This is the method taught in the Mahaparinirvana Sutra, and also the direct path of the Chan or Zen school. May you have swift progress on the path to enlightenment, sadhu.