Mark 12

1 Although Jesus said He would not answer their question, He does so indirectly here.

The vineyard owner represents God. The vineyard is probably a combination of the Promised Land and the Law of Moses. God has provided protection and production capabilities for the vineyard. The vinedressers are the Israelites. God has "leased" His special vineyard to them. The owner traveling to the far country is not an admission of Deism, but represents delayed accountability.

2 The servants are the prophets. God expected the Israelites to produce spiritual fruit (e.g., Gal 5:22-23). The prophets were sent periodically to hold Israel accountable for that fruit.
3 They did not give God what was rightfully His. Instead, they abused and killed the messengers.
6 The prophets were ordinary people who had been given special authority by God. However, the Israelites did not give them proper respect. Finally, God sent His own Son -- a co-equal in the Godhead. If they would respect anyone, it would be His Son, since the Son carried the same authority as the Father (thus, Jesus tells the Jews where His authority comes from).
7 The foolish vinedressers believe that if they kill the owner's son they can keep the vineyard for themselves (illegally, of course).

The Jews had the Law of Moses, but they added traditions and practices that circumvented the Law and made their religion fruitless and of no value to themselves or to God. Therefore, God sent His Son, Jesus, to set matters straight. However, the Jews did not want to be held accountable to God, so they would kill Jesus in an attempt to run their religion their own way.

8 Here, there is a parallel between the vineyard and Jerusalem. The Jews (indirectly) took Jesus outside Jerusalem to kill Him.
9 Although the vinedressers felt they had escaped accountability, there would come a day when the owner would settle his accounts.

This does not appear to be a picture of Judgement Day, since the vineyard is given to others. Instead, the story predicts the transfer of spiritual fruitfulness from the Israelites to the Gentiles.

10 The verse quoted is Psa 118:22-23. Jesus confirms that Israel was appointed the builders of God's kingdom. Jesus is the keystone that would hold the Kingdom together. The Jews would reject Him, and in the end, their own attempts at spiritual construction would collapse. However, Jesus still is the keystone to the Kingdom, and God has reassigned the spiritual construction to the Gentiles and those Jews that do believe Him.
11 It is amazing that God's plan can still succeed even when He entrusts it to suborn and fallible people.
12 The parable was clear enough so that all the people understood exactly what Jesus was saying. The religious leaders were insulted by the parable, but they would not attempt to arrest Him for fear that His loyal followers would revolt.
28 This scribe was able to see that Jesus had incredible knowledge and wisdom. This question was posed not merely to test Jesus, but to receive an answer from Him who seemed to know the mind of God (see parallel account in Mat 22:36).

One Bible study says that rabbis have determined that there are 613 commands in the Old Testament: 365 negative commands ("thou shall not...") and 248 positive commands ("thou shall..."). Knowing the legalistic nature of the religious leaders, we can only imagine the endless debates about which of these commands were most important (and conversely, which commands can be ignored).

Note that scribes (a.k.a., teachers of the law) were considered to be among the ultimate authorities on the Scriptures since their job involved making accurate copies of the sacred documents.

29 Jesus quotes Deu 6:4-5. These are the words of Moses shortly after reading the Ten Commandments. Obeying this command covers the first four of the Ten Commandments.
31 Man is created in God's image. Because we share God's image, we are entitled to the respect that goes with it. To obey this command covers the remaining of the Ten Commandments.
33 The last part of the scribe's statement resembles a theme repeated often in the Scriptures (e.g., 1 Sam 15:22). Sacrifices are not mentioned in the Ten Commandments. They are still important, as is also repeated often, but Jesus would become the ultimate sacrifice. When we believe in Jesus, it is as if we had made all the sacrifices described in Scripture.
34 What the scribe was missing was faith in Jesus. Perhaps the final key would turn when he saw or heard about His death and resurrection.

Jesus had answered the challenges of the religious leaders so well that they did not know what else they might ask. Jesus' superior wisdom was unquestionable.