And now the third day was come, and the morning appeared: and behold thunders began to be heard, and lightning to flash, and a very thick cloud to cover the mount, and the noise of the trumpet sounded exceeding loud; and the people that was in the camp, feared.
Exodus 19:14 And Moses came down from the mount to the people, and sanctified them. And when they had washed their garments,
Exodus 19:15 He said to them: Be ready against the third day, and come not near your wives.
Exodus 19:16 And now the third day was come, and the morning appeared: and behold thunders began to be heard, and lightning to flash, and a very thick cloud to cover the mount, and the noise of the trumpet sounded exceeding loud; and the people that was in the camp, feared.
Exodus 19:17 And when Moses had brought them forth to meet God, from the place of the camp, they stood at the bottom of the mount.
Exodus 19:18 And all Mount Sinai was on a smoke: because the Lord was come down upon it in fire, and the smoke arose from it as out of a furnace: and all the mount was terrible.
The verse centers on "light", "third", "come", "morning", "appeared", "behold", "thunders", and "began". It is saying that the verse draws attention to "light" and "third", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 15's "He said to them Be ready against..." into verse 17's "And when Moses had brought them forth...", so "light" and "third" belong inside that flow. In Exodus context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "light" and "third" with trust shaped by these words, not by a vague optimism outside the passage.