The original manuscript reads for of; both words are written rather faintly in 𝓞 (at least when compared with the other words in the line). It does not appear that the of is erased, although there is some slight ink smearing. The printer’s manuscript and the first two printed editions also have for of. The expression “a state of awful fearful looking for of the fierce indignation of the wrath of God” is, to be sure, a difficult reading.
The 1840 edition attempted to deal with this difficult expression by placing a comma between the for and the of. And the RLDS textual tradition has continued with both words and the comma separating them. The idea behind this punctuation change is to make sure that looking for belongs together as the nominal gerundive form for the prepositional verb look for. In the Book of Mormon text, the nominal gerundive typically places an of between the adverbial element of a phrasal verb and its complement, as in these examples:
Alma 40:14 therefore fits into this pattern: “a state of awful fearful looking for of the fiery indignation of the wrath of God”.
The 1841 British edition (which was set from the 1837 edition) deleted the of, thus removing this difficult reading from the text; all subsequent LDS editions have followed this emendation. One could argue that the extra of here is an error resulting from the many occurrences of of in this passage: “now this is the state of the souls of the wicked yea in darkness and a state of awful fearful looking for of the fiery indignation of the wrath of God upon them”. This error is supported by the following nearby example where Oliver Cowdery initially inserted in 𝓟 an extra of; 𝓞 is extant here and the of is lacking:
And as in Alma 40:14, the surrounding text in Alma 37:19 contains a number of of ’s that could have interfered in the correct transmission of the text: “of many of thousands of the Lamanites to the knowledge of the truth”.
Despite the difficulty of the earliest reading in Alma 40:14, there is one very striking passage in the King James Bible that shows without a doubt that here the original Book of Mormon reading is no mistake:
The parallelism with the Book of Mormon reading (“a state of awful fearful looking for of the fiery indignation of the wrath of God upon them”) shows that the of is fully intended in the Book of Mormon text. Therefore the of will be restored in the critical text.
Summary: Restore in Alma 40:14 the of that separates the gerundive looking for and its following complement, “the fiery indignation of the wrath of God upon them”; Hebrews 10:27 provides conclusive evidence that the of (the reading in 𝓞) is correct.