The Long Āgama Sūtra 3.25

3.25

「時，大典尊於彼城東造閑靜室，於夏四月，即於彼止，修四無量，然彼梵天猶不來下，典尊自念：『我聞先宿舊言，於夏四月，修四無量，梵天下現。今者寂然，聊無髣髴。』時，大典尊以十五日月滿時，出其靜室，於露地坐，坐未久頃，有大光現，典尊默念：『今此異光，將無是梵欲下瑞耶？』

“‘Great Govinda then had a secluded abode built near his city and retired there to cultivate the four immeasurables during the four months of summer. Afterward, Brahmā didn’t come down to him. Govinda thought to himself, “I’ve heard ancient sayings from previous generations that when someone cultivates the four immeasurables during the four months of summer, Brahmā comes down and appears. It’s tranquil now, but there’s not even a momentary blur of him to be seen.”

“‘Great Govinda emerged from his quiet abode on the 15th-day full moon to sit on open ground. Only a moment after sitting, a bright light appeared. Govinda thought to himself, “Now, this is a strange light! Perhaps this is a sign that Brahmā is going to come down?”