“Look!” The Greek word is idou (#2400 ἰδού), and it is used to get our attention. See commentary on Matthew 1:20 (“Look!).
“proper time.”Kairos (#2540 καιρός) can mean time in the sense of “proper, right, or appropriate time” (BDAG). Much like a parent might say to a fifteen year old, “you’ll be ready to date when it is time,” or “when it’s time, we’ll know.” In these cases “time” means, the right time, the appropriate time. The Greek word for “time” was also used in this sense.
“you will be silent and not able to speak.” Although at first blush this may seem harsh, it was really a blessing in disguise. Although no doubt inconvenient at times, that Zechariah could not speak was not painful and was enough of a blemish that he would not have been allowed to minister as a priest, but, as per the Law of Moses, he could still live off the priestly income (Lev. 21:21-24). Zechariah and Elizabeth would have had an immense amount of adjusting to do to prepare for a baby, and this “blemish” allowed Zechariah the time to dedicate himself to the changes that would have to be made to properly prepare not just for the birth of a baby, but prepare for the birth of the forerunner of the Messiah.