增壹阿含經 12.1.p30

12.1.p30

“Furthermore, a monk abandons perception and examination, possesses an inner joy, and his mind is unified. Having achieved the absence of perception and examination, he is mindful, calm, joyous, and happy, and he abides in the second dhyāna. In this way, a monk contemplates principles as principles as an abode of mindfulness.