Focus on the nose or the abdomen?

In the practice of meditation the question of whether to focus on the breath in the nose or in the abdomen often comes up. It is widely believed that to focus on the nose with the meditation word "Bud-dho" is more conducive to the practice of the Samatha method, leading to various Jhanas. To focus on the abdomen is more widely used for the Vipassana method, with aims at building mindfulness rather concentration, leading to the arising of different levels of insight.

However many people tend to make the mistake of perceiving Samatha and Vipassana as 2 separate methods. In reality they are one and you cannot practice one without the other. With regard to Samatha, you have to train the mind to reach Jhana by concentrating on the fine breath going in and out of the nose, to the exclusion of everything else. Once the 5 factors of Jhana appear, you can slowly refine them until nothing other than one-pointedness and equanimity of mind are left. After you leave that state you must immediately use that calmed and subdued mind to review the various aspects of the aggregates, so that clear Jnana (knowledge) about their true nature can arise. This is the Vipassana aspect in Samatha.

But with regard to Vipassana, to have the intention to build concentration up to the point of Jhana would be wrong. The noting of the abdomen movement is not for you to do get into Jhana, but rather to simply establish mindfulness in your own body (kayanussati). While noting the abdomen movement, one also notes any feelings (vedananussati) or thoughts (cittanussati) that arise. If one can maintain powerful and stable mindfulness in these 3 things, that is your Samatha aspect within Vipassana. Once mindfulness becomes full, it will enable you to see the nature of these 3 things, which are none other than the aggregates. Mindfulness of the Dhamma (Dhammanussati) will arise from there. These are the 4 foundations of mindfulness leading to the end of suffering.

Whether it is Samatha-Vipassana or Vipassana-Samatha, if you try to practice them as 2 separate methods, your meditation would lack power and this will make it very difficult for you to achieve good results. Therefore you should always bear in mind that they work hand in hand and once you decided where best to focus, stay true to the method until the very end.