स एतास्तिस्रो देवता अभ्यतपत्तासां तप्यमानानाँ रसान्प्रावृहदग्नेर्ऋचो वायोर्यजूंषि सामान्यादित्यात् ॥ २ ॥
In plain words
He then focused his meditative heat upon those three deities. As they were thus heated, he drew forth their essences: the Ṛk verses from Agni, the Yajus formulas from Vāyu, and the Sāman chants from Āditya.
Close to the Sanskrit
He brooded upon these three deities. From those deities being heated, he extracted their essences: the Ṛk verses from Agni, the Yajus formulas from Vāyu, and the Sāman chants from Āditya.