My point was really just to point out the 'type' teaching of the rock as a picture of Christ. The first time (Ex 17.6) God tells Moses to strike the rock for water to flow, the later times (I thought there were more, but looks like just the one - Num 20) God told Moses only to speak to the rock, not to strike it. The rock is a picture of Christ (I think that comes up a number of times, even in the NT), and the first striking of the rock is a picture of the crucifixion, so striking the rock on the second occasion spoiled the type because Christ is only to be crucified the once.
But there are many 'types' in the OT. Some are types of Christ, some types of Satan, some other aspects of the future. In a way, the types are part of prophecy and a picture of what is to come. Seeing that really helps to bring the OT alive for study. They are not all perfect types, but still good to see them.
Some more quick ones:
Moses vs Joshua - already mentioned above.
Saul/David/Solomon - the only kings of united Israel are a picture of: the usurping anti-Christ; the conquering Christ at his return; and the king of peace ruling for 1000yrs. (Even though Solomon was not a good king, the kingdom was at its peak under his rule).
Joseph (the one in Egypt, not Mary's husband) - a number of similarities.
The sacrifice of Isaac by Abraham as a picture of the crucifixion.
All the feasts (most obviously the Passover) represent stages of the end times. Some of these are fulfilled, some not yet.
And even the Sabbath, the day of rest represents Israel's 1000 years rest in the Millenium (especially since today is around 6000yrs from Adam, then the coming millenium; think also in Peter (somewhere) he says that to God 'a day is as a thousand years and a thousand years as a day'). Why else was working on the Sabbath punishable by death? Seems disproportionate, but it spoils the type. God really didn't want that happening.
Nebuchadnezer is a type of the anti-Christ, eg. setting up the statue to be worshipped, etc. (Though he repented and turned out okay)
Jonah, the 3 days in the fish/whale - but Jesus already pointed that one out.
And Paul already pointed out Moses being accepted only the second time, just as Jesus will be accepted the second time.
The whole OT, in different ways, is full of types, mostly pointing to Christ.