The first phrase here is a little problematic. In our modern way of speaking, we would want to have our children believe that we know of ourselves - for us that would mean that we had a personal conviction/knowledge/testimony. For Alma, the phrase does not appear to be used in that way. It appears to mean that “know of myself” is equivalent to “know by thinking it out”. In this case the clues are the contrasting phrases which follow; “not of the temporal but of the spiritual, not of the carnal mind but of God”. These serve as definitions of the way in which Alma has knowledge. They are not “of myself”, “of the temporal”, “of the carnal mind”. Those are contrasted with the positives “of the spiritual” and “of God”. There is no clear dual set for “I know of myself”, but the grammar of the sentence supports that phrase as parallel to the negative statements, not the positive.
To restate this phrase, the more modern meaning might be “I would not that ye think that I know by study – not of the temporal learning, but rather of the spiritual learning, not from the learning of man, but the mind/teaching of God.”