Jesus told the parable of the fig tree to illustrate the certainty of what He had prophesied. He then gave other assurances of fulfillment. Luke omitted Jesus' statement that no one would know the day or hour when He would return (Matt. 24:36; Mark 13:32). He may have felt that this would weaken the force of these predictions, and he recorded a similar statement later (Acts 1:7). He also omitted Jesus' reference to the sign of Noah and the parables of the one taken and the other left behind (Matt. 24:37-41). He had recorded this teaching earlier when Jesus gave it in another context (17:26-27, 34-35).
21:29-31 This parable illustrates the truth that the kingdom's appearing will follow the signs that Jesus just identified (vv. 10-11, 25-26). It will follow as certainly as summer follows the budding of trees in the spring. Jesus here connected the beginning of the kingdom with His return to the earth (v. 27).
Luke is the only recorder of this teaching who included the phrase "and all the trees."The fig tree was a symbol of Israel. The budding of the fig tree could therefore be a figurative reference to Israel's revival (cf. Isa. 27:12-13; Matt. 24:31; Mark 13:27). Similarly the budding of all the trees may refer to the revival of other Gentile nations. Luke may have included this phrase to help his Gentile readers understand that Jesus' words deserved a literal as well as a symbolic interpretation here.
21:32 This verse begins Jesus' final word confirming the certainty of His prophecy. He introduced it with the solemn "Truly I say to you"or "I tell you the truth."
"This generation"refers to the unbelieving Jews who were alive when Jesus spoke, as it usually does in the Gospels (cf. 3:7; 7:31; 9:41; 11:29-32, 50-51; 17:25; Mark 11:14; Acts 2:40). Jesus probably meant that that generation would not disappear until the fulfillment of all that He had predicted had begun.466The destruction of Jerusalem was the beginning of the fulfillment of what Jesus had predicted in this discourse. Obviously all the things that He predicted here did not happen within the lifetime of His hearers. He evidently regarded the beginning of fulfillment as a guarantee of complete fulfillment. This was a common Semitic viewpoint. The Semites regarded a part of the whole as the whole (cf. Deut. 26:5-10; 1 Kings 13:32; Jer. 31:5; 2 Sam. 5:6-10; Rev. 14:1; 22:1; Rom. 15:19-24). The name that some scholars have given this viewpoint is representative universalism.467
21:33 Heaven and earth is a merism for the universe. Jesus meant that the universe would someday end (cf. Rev. 21:1), but His Word would not end (cf. 16:17; Ps. 102:25-27; 119:160; Isa. 40:6-8; 51:6; Matt. 5:18). This is a strong way of affirming the certainty of what He had just predicted. It also implied that Jesus had divine authority.
