The following descriptions in the Upakkilesa Sutta further show how he find his way into the first four Jhanas, which he later considered as “samma samadhi”.
“When Anuruddha, I realized that doubt is an imperfection of the mind, I dropped out of doubt, an imperfection of the mind. When I realized that inattention … sloth and torpor … fear … elation … inertia … excessive energy … deficient energy … desire … perception of diversity … excessive meditation on the ways, I abandoned excessive meditation on the ways, an imperfection of the mind.” “When Anuruddha, I realized that doubt is an imperfection of the mind, I dropped out of doubt, an imperfection of the mind. When I realized that inattention … sloth and torpor … fear … elation … inertia … excessive energy … deficient energy … desire … perception of diversity … excessive meditation on the ways, I abandoned excessive meditation on the ways, an imperfection of the mind, so I thought, 'I abandoned these imperfections of the mind.' Now the concentration will develop in three ways. ..And so, Anuruddha, develop concentration with directed thought and sustained thought; developed concentration without directed thought, but only with the sustained thought; developed concentration without directed thought and without thought sustained, developed with the concentration ecstasy; developed concentration without ecstasy; develop concentration accompanied by happiness, developing concentration accompanied by equanimity … When Anuruddha, I developed concentration with directed thought and sustained thought to the development … when the concentration accompanied by fairness, knowledge and vision arose in me: 'My release is unshakable, this is my last birth, now there are no more likely to be any condition.'”[16]
Nanamoli, Bhikkhu (trans.) (1995, ed. Bhikkhu Bodhi). The Middle Length Discourses of the Buddha: A New Translation of the Majjhima Nikaya. Boston: Wisdom Publications. ISBN 0-86171-072-X.