Various scholars have attempted to use the numerous early sources to trace an "ur-text" i.e. the original satipaṭṭhāna formula or the earliest sutta. Bronkhorst (1985) argues that the earliest form of the satipaṭṭhāna sutta only contained the observation of the impure body parts under mindfulness of the body, and that mindfulness of dhammas was originally just the observation of the seven awakening factors. Sujato's reconstruction similarly only retains the contemplation of the impure under mindfulness of the body, while including only the five hindrances and the seven awakening factors under mindfulness of dhammas. According to Analayo, mindfulness of breathing was probably absent from the original scheme, noting that one can easily contemplate the body's decay taking an external object, that is, someone else's body, but not be externally mindfull of the breath, that is, someone else's breath.
