Vilaskadival said: “I feel that apart from Kamma and Kamma vipaka, the body pain or pleasure (dukkha vedana and sukha vedana) are conditioned by niyama as under…..”.
I know this a well-established concept. However, the problem lies at the incorrect explanations of the five niyama. I have briefly discussed this under #2 in the post,”What is Kamma? – Is Everything Determined by Kamma?“.
Basically, all other four niyama (or principles or unchanging universal laws) help enforce the kamma niyama.
Kamma (what is done with the mind), while not deterministic (otherwise Nibbana will be impossible to attain), is a pre-requisite for anything to happen. For example, dhamma niyama is basically, Tilakkhana, Paticca Samuppada, etc. Citta niyama deals with fundamentals of how citta vithi operate (17 cittas in a pancadvara vithi, sobhana and asobhana cetasika, etc). Bija niyama is how kamma bija bring results under suitable conditions (which involves dhamma niyama with Pattana Dhamma). Utu niayama deals with the viparinama nature of a sankata. These are all inter-related.
I am looking for relevant suttas, but found only this one on dhamma niyama: “Uppādā Sutta (AN 3.136)” so far. It starts with “Uppādā vā, bhikkhave, tathāgatānaṃ anuppādā vā tathāgatānaṃ, ṭhitāva sā dhātu dhammaṭṭhitatā dhammaniyāmatā. Sabbe saṅkhārā aniccā..”.
Translated: “Bhikkhus, whether there is a Tathagata (Buddha) is present in this world or not, all sankhara always have anicca nature (that is a dhamma niyama)…”.
It is always: “Mano pubbangma dhamma…”. Nothing happens without mind being a precursor. Kamma or sankhara are what we do with our minds. Also see the recent post: “Does Bodily Pain Arise Only Due to Kamma Vipāka?“.