A question: without radio, television or the Internet, how could he have heard?
Answer: probably by means of a bat kol, a Heavenly Voice. Pir’kei Avot says (6:2), “Every day a bat kol comes forth from Mount Horev…”
All very well, but if there was a bat kol, didn’t other people also hear the message?
One explanation is that not everybody is tuned in to messages from On High. A great deal depends on the nature, character and circumstances of the listener. Most people are so taken up with their day-to-day concerns that the kol d’mamah dakkah, the “still, small voice” can’t penetrate their consciousness.
In today’s world, we tend to turn up the noise around us to the extent that there is no chance that a Divine message will get through.
If I may be personal, let me recall a moment a few weeks ago when my wife and I were in a noisy shop and my cell phone started vibrating. I answered it but couldn’t make out who was calling or what they wanted. I had to go out into the street, where, despite the traffic noises, I got the gist of the message.
When it comes to messages from the Almighty, most people unfortunately neither hear nor want to hear.
Yitro must have been a spiritually-minded human being who was acutely conscious of every quiet Divine communication.