Lebanon shall be turned into a fruitful field

King James Bible
"Is it not yet a very little while, and Lebanon shall be turned into a fruitful field, and the fruitful field shall be esteemed as a forest?"

"Wesley's Notes

29:17 As a forest - The forest of Lebanon, which was a barren mountain, shall by God's providence, become a fruitful and populous place; and these places which are now fruitful and populous, shall then become as barren and desolate, as that forest. This is a prophecy of the rejection of the Jews, and of the calling of the Gentiles.

Jamieson-Fausset-Brown Bible Commentary

17. turned-as contrasted with your "turnings of things upside down" (Isa 29:16), there shall be other and better turnings or revolutions; the outpouring of the Spirit in the latter days (Isa 32:15); first on the Jews; which shall be followed by their national restoration (see on [739]Isa 29:2; [740]Zec 12:10) then on the Gentiles (Joe 2:28).

fruitful field-literally, "a Carmel" (see on [741]Isa 10:18). The moral change in the Jewish nation shall be as great as if the wooded Lebanon were to become a fruitful field, and vice versa. Compare Mt 11:12, Greek: "the kingdom of heaven forces itself," as it were, on man's acceptance; instead of men having to seek Messiah, as they had John, in a desert, He presents Himself before them with loving invitations; thus men's hearts, once a moral desert, are reclaimed so as to bear fruits of righteousness: vice versa, the ungodly who seemed prosperous, both in the moral and literal sense, shall be exhibited in their real barrenness.

Matthew Henry's Concise Commentary

29:17-24 The wonderful change here foretold, may refer to the affairs of Judah, though it looks further. When a great harvest of souls was gathered to Christ from among the Gentiles, then the wilderness was turned into a fruitful field; and the Jewish church, that had long been a fruitful field, became as a deserted forest. Those who, when in trouble, can truly rejoice in God, shall soon have cause greatly to rejoice in him. The grace of meekness contributes to the increase of our holy joy. The enemies who were powerful shall become mean and weak. To complete the repose of God's people, the scorners at home shall be cut off by judgements. All are apt to speak unadvisedly, and to mistake what they hear, but it is very unfair to make a man an offender for a word. They did all they could to bring those into trouble who told them of their faults. But He that redeemed Abraham out of his snares and troubles, will redeem those who are, by faith, his true seed, out of theirs. It will be the greatest comfort to godly parents to see their children renewed creatures, the work of God's grace. May those who now err in spirit, and murmur against the truth, come to understanding, and learn true doctrine. The Spirit of truth shall set right their mistakes, and lead them into all truth. This should encourage us to pray for those that have erred, and are deceived. All who murmured at the truths of God, as hard sayings, shall learn and be aware what God designed in all. See the change religion produces in the hearts of men, and the peace and pleasure of a humble and devout spirit." (http://bible.cc/isaiah/29-17.htm)

"Lebanon

Lebanon is the ancient and modern name of the region immediately north of what is called today the state of Israel. Anciently Lebanon was known for its impressive cedar forests (1 Kgs. 4:33; 5:6; 2 Ne. 12:13; 24:8). Isaiah prophesied that the land would again become a fruitful field, a sign associated with the coming forth of the Book of Mormon and the restoration of the gospel (Isa. 29:17-18). Modern prophets indicate that this is being fulfilled (Smith, 98).

In the early nineteenth century, Lebanon (specifically Beirut) became for a time the headquarters of Protestant efforts to proselyte Jews and Muslims of the Near East. During Orson Hyde’s famous journey to Jerusalem in 1841 to dedicate the Holy Land for the gathering of Abraham’s posterity, he docked in Beirut, where he regained his health before continuing his mission. In the last decades of the nineteenth century the country became part of the LDS Church’s Turkish Mission, opened by Elder Jacob Spori in 1884. In 1921 Lebanon became part of the Armenian Mission; in 1933 part of the Palestine-Syrian Mission; and in 1950 part of the Near East Mission that was discontinued in January 1951. Between 1965 and 1975, when missionaries from the Swiss Mission served in Beirut, a branch of the Church operated there, but civil war forced Church activities to cease. A Church branch was reestablished in 1990, and by the beginning of the year 2000 this branch held 139 members. The Church’s presence in Lebanon has generally been tenuous, tied to the fortunes of the country itself, which has suffered variously from war, political instability, and material privations." (http://globalmormonism.byu.edu/?page_id=85)

In ancient times, Lebanon housed large forests of the Cedars of Lebanon, which now serve as the country's national emblem.[60] However, centuries of trading cedar trees, used by mariners for boats, and the absence of any efforts to replant them have depleted the country's once-flourishing cedar forests.[60]
(http://en.wikipedia.org/wiki/Lebanon)