Is the following introduction to Kp 9 from commentary? I couldn’t find it in either Kp 9 or Sn 1.8.
"Translator’s introduction: While the Buddha was staying at Savatthi, a band of monks, having received subjects of meditation from the master, proceeded to a forest to spend the rainy season (vassana). The tree deities inhabiting this forest were worried by their arrival, as they had to descend from tree abodes and dwell on the ground. They hoped, however, the monks would leave soon; but finding that the monks would stay the vassana period of three months, harassed them in diverse ways, during the night with the intention of scaring them away.
Living under such conditions being impossible, the monks went to the Master and informed him of their difficulties. Thereon the Buddha instructed them in the Metta sutta and advised their return equipped with this sutta for their protection.
The monks went back to the forest, and practicing the instruction conveyed, permeated the whole atmosphere with their radiant thoughts of metta or loving-kindness. The deities so affected by this power of love, henceforth allowed them to meditate in peace.
The discourse gets divided into two parts. The first detailing the standard of moral conduct required by one who wishes to attain Purity and Peace, and the second the method of practice of metta."
Thanks and metta,