Culture: The tradition of seeing omens in the sky is part of the Mesoamerican culture, and Sahagún reports that the Aztecs interpreted heavenly omens as predicting the arrival of the Spaniards:
Ten years before the Spaniards arrived here, an omen of evil first appeared in the heavens. It was like a tongue of fire, like a flame, like the light of dawn. It looked as if it were showering [sparks], as if it stood piercing the heavens. It was wide at the base, it was pointed at the head. To the very midst of the sky, to the very heart of the heavens it stood reaching; to the very midpoint of the skies it stood stretched as it was seen. It was there to the east when it thus came forth at midnight; it looked as if day had dawned, day had broken. Later, the sun destroyed it when he arose. For a full year [the sign came forth].
This passage in the Florentine Codex almost certainly describes a comet. It does not precisely fit Samuel’s description. It does, however, reflect the understanding that signs in the heavens could be omens of future events. Most interesting is the description of the omen’s brightness—light like the sun (“as if day had dawned”)—at a time when the sun was not shining.