Some said Buddha taught sutta and Vinaya only.
This is not true.
Buddha’s teachings are not limited only to Suttas. We should not step over the line and belittling Buddha’s great wisdom.
The Dhamma was preached to all Devas and human beings. That’s why the Master was called “Teacher of Gods and Men” (Satthadevamanussanam).
The Dhamma is not necessary only limited to human realm. There are many teachings directed to Devas, which later on re-directed to human beings. One best example is Mangala sutta and Parabhava Sutta, these two Suttas were given on the request of a Deva…and the Buddha answered the request and delivered two Suttas to that Deva. Which later redirected to us human beings via Bhante Arahant Ananda Thera. So too, Abhidhamma teachings were given to Māyādevaputta (former mother of Bodhisatta Siddhartha Gautama, Queen Maha Maya) and aiming for all Deva realms during Buddha’s three months Vassa in Tavatimsa Heaven sitting on the throne of Sakka Devaraja. And this later redirected to human beings via Bhante Arahant Sariputta Thera and his 500 disciples.
Bhante Arahant Ananda Thera was not only the bearer of Suttanta but other mode of teachings too. He said in total, 84000 dhammakkhandhas he memorised as pure Dhamma, with 82000 of which Buddha’s words, 2000 are of Savakas’ words. And not only Bhante Ananda Thera remember the Dhamma, but there are many many other Arahants capable to do so by their ability.
And Buddha taught not only Suttas, he taught other sections such as veyyakarana, Jataka, itivuttaka, etc…which is now under Khuddaka Nikaya. And Abhidhamma was from Khuddaka Nikaya once under veyyakarana section, then rearranged to fit into Abhidhamma Pitaka during the third council as Bhante Arahant Moggaliputta Tissa Thera completing Kathavathu, defeated every misguided schools of early Buddhism (which in the end these schools flee and spread outside of India while not prosper in Asoka Kingdom).
And in the days of Buddha, those Bhikkhus focused only in Sutta study and recital were called “Suttantikā”. Then, those who are experts in Vinaya rules were called “Vinayadharā” the Bhikkhus that engage in Abhidhammakatham (topics on Abhidhamma) were called “Dhammakathikā” (why they are called “engaged” because of the nature of Abhidhamma, as shown in Dhammasaṅgaṇī, which often involving explanation of terms and concepts). Such grouping is found in Vinaya Pitaka. And Bhante Arahant Moggallana Thera was one of the Dhammakathikā as shown in Mahagosingasutta:
“Idhāvuso sāriputta, dve bhikkhū abhidhammakathaṁ kathenti, te aññamaññaṁ pañhaṁ pucchanti, aññamaññassa pañhaṁ puṭṭhā vissajjenti, no ca saṁsādenti, dhammī ca nesaṁ kathā pavattinī hoti. Evarūpena kho, āvuso sāriputta, bhikkhunā gosiṅgasālavanaṁ sobheyyā”ti…“Sādhu sādhu, sāriputta, yathā taṁ moggallānova sammā byākaramāno byākareyya. Moggallāno hi, sāriputta, dhammakathiko”ti.
And in the Mahāparinibbānasutta, Buddha said “Dhamma-Vinaya”, and Dhamma here means all those 9 aspects of teachings. Not only Suttanta.
And while Abhidhamma teachings were originated from Lord Buddha, the way of scripture arrangement originated from Bhante Arahant Sariputta Thera, the General of Dhamma. Now even Sarvāstivāda admitted the Abhidharma was from Sariputra in their record. Since both large schools also agreed that Arahant Sariputta Thera was the bearer of Abhidhamma scriptures, there hardly any doubt for its value.
And Abhidhamma Pitaka was written down on Ola leaves during the Fourth Council at Aluvihara, Sri Lanka. If you telling me Abhidhamma Pitaka is fake, then you are directly challenge the Vinaya quality of these ancient monks. For if the Abhidhamma Pitaka is fake (according to EBT idea), these ancient monks would have made a grave mistake and this bad kamma is super serious. If these monks able to make mistake such as this, their credibility is very low then…why would you still take confidence in this Sutta Pitaka and Vinaya Pitaka given by them? Don’t forget, all Pāli suttas that we can read online now, is due to the existence of these Pali Suttas recorded by these ancient monks. From them, we get the scriptures. And no, don’t tell me there is another source to get the Pali Suttas because that would not be “Theravada”.
And not to say only Suttanta aren’t sufficient, but if someone prone to confusion, mental problem, uncontrollable acts of Papanca, misinterpretation, having strong attachment to wrong view, lacking of wise consideration…to only read Suttanta aren’t enough. One must take in the entire teaching of the Buddha as a whole to work on Maggaphala attainments.