Ecclesiastes: chapter 12

As to thy question concerning the 12th chapter of Ecclesiastes: This is prophecy regarding the coming of Jesus in that book, the signs and marks of which were fulfilled with the appearance of the Promised One of the Bible; [the Old Testament] but since the Jews did not understand the meaning thereof, so they denied Jesus and— God forbid! —said that He was the deformed (Antichrist). Then it is said by Jesus in the Gospel, that similar signs would appear in the “last day”—or in other words—in the day when Christ will come the second time in this world. 

- ‘Abdu’l-Baha  (‘Tablets of ‘Abdu’l-Baha, vol. 1)

Isaiah: chapter 54

As to thy question concerning the 54th chapter of Isaiah: This chapter refers to the Exalted Leaf, the mother of ‘Abdul-Baha. As a proof to this it is said: “For more are the children of the desolate, than the children of the married wife.” Reflect upon this statement and then upon the following: “And thy seed shall inherit the Gentiles and make the desolate cities to be inhabited.” And truly the humiliation and reproach which she suffered in the path of God is a fact which no one can refute. For the calamities and afflictions mentioned in the whole chapter are such afflictions which she suffered in the path of God, all of which she endured with patience and thanked God therefor and praised Him, because He had enabled her to endure afflictions for the sake of Baha’. During all this time, the men and women [violators of the Covenant] persecuted her in an incomparable manner, while she was patient, God-fearing, calm, humble and contented through the favor of her Lord and by the bounty of her Creator. 

- ‘Abdu’l-Baha  (‘Tablets of ‘Abdu’l-Baha, vol. 1)

Revelation: chapter 21, verses 10 and 17

Thou hast asked in regard to the 10th verse of the 21st chapter of Revelation and to the 17th verse:

Know that the firmament of the bright sun of the world of possibilities is divided into twelve sections, according to mathematical principles, which are called the twelve constellations; likewise, the Sun of Truth manifests and pours forth His bounty in twelve constellations of holiness. By these constellations are meant holy souls who are the manifestations of purity and the dawning-points of the lights of Unity. Observe that in the day of His Holiness the Speaker of God (Moses), there were twelve holy souls who were the leaders of the Truth. In like manner, in the cycle of His Holiness the Spirit (Jesus Christ), note that there were twelve apostles under the shadow of the light of the Most High, and the Sun of Truth was manifested through those bright dawning-places like unto the phenomenal sun. Likewise, in the time of His Holiness Mohammed, consider that there were twelve dawning points of holiness who were the manifestations of confirmation. Such is the case.