When Krsna opened His mouth, His mother saw innumerable universes inside. This is Krsna. Anor aniyan mahato mahiyan. Krsna enters within the universe, but at the same time millions of universes are within His mouth. This is the explanation of "greater than the greatest and smaller than the smallest." Of course, although Mother Yasoda saw Krsna's display, she could not believe it, because she never thought that Krsna is the Supreme Personality of Godhead. She always thought, "He is my tiny child." That's all. "I have to take care of Him." These are called parental feelings — vatsalya-rasa.

From BTG, March 2002

Based on a lecture by Srila Prabhupada on November 29, 1972