2v.269 "The one of broad wisdom has indeed found
The opening in the midst of confinement,
The Buddha who discovered jhāna,
The withdrawn chief bull, the sage." [n.151] At AN IV 449–51 the Venerable Ānanda gives a detailed explanation of the verse. Readings of the aorists in pādas b and c differ among the various eds., but without affecting the meaning. Spk explains that there are two kinds of confinement (sambadha): confinement by the five hindrances and confinement by the five cords of sensual pleasure, the former being intended here. The opening pleasure, the former being intended here. The opening (okasa) is a name for jhāna. In the analysis given by Ānanda, however, confinement and the opening are explained sequentially: first the five cords of sensual pleasure are called confinement and the first jhāna the opening; then vitakka-parajika are confinement and the second jhāna the opening; and so on, culminating in the destruction of the āsavās as the final opening.
The withdrawn chief bull (paṭilinanisabho): The Buddha was called a chief bull at SN1.38. At AN II 41,29–32 a bhikkhu is said to be paṭilina, "withdrawn," when he has abandoned the conceit "I am."

3v.270 "Even in the midst of confinement they find it,
O Pañcalacaṇḍa," said the Blessed One,
"The Dhamma for the attainment of Nibbāna—
Those who have acquired mindfulness,
Those perfectly well concentrated." [n.152] The "Dhamma for the attainment of Nibbāna" (dhammaṁ nibbanapattiya) is presumably the Noble Eightfold Path. Spk-pṭ: This young deva had been an obtainer of the first jhāna in a previous existence. He spoke his verse to extol the Blessed One for obtaining the bliss of jhāna. The Buddha’s reply is intended to show that the first form-sphere jhāna is a mere fragment of the infinite and immeasurable qualities of a Buddha. By mindfulness (sati) he refers to the mindfulness of insight and of the noble path. Well concentrated (susamahita) signifies both mundane and supramundane concentration. sn.i.49

2"Sambādhe vata okāsaṁ,
Avindi bhūrimedhaso;
Yo jhanamabujjhi buddho,
Paṭilīnanisabho munī"ti.

3"Sambādhe vāpi vindanti, (pañcālacaṇḍāti bhagavā)
Dhammaṁ nibbānapattiyā;
Ye satiṁ paccalatthaṁsu,
Sammā te susamāhitā"ti.