To strike or smite, when used in the Bible, means to attack, harm or destroy, and is usually in reference to an attack on someone's knowledge and intellect. This is actually true both when evil people strike good people, trying to destroy their understanding of spiritual things, and when the Lord is pictured as striking people (with plagues in Egypt, for example), which most often represents the dulling of the intellect and destruction of knowledge in evil people to prevent them from doing spiritual harm to others.

(Odkazy: Apocalypse Revealed 498; Arcana Coelestia 1487, 6758, 6765, 7330, 7871, 9007, 9034, 9081, 9126, 10510)

9126. 'And is struck, and he dies' means if in this situation harm is done to it, so great that it is wiped out. This is clear from the meaning of 'being struck', when said of truth or good, as being injured or suffering harm, as in 9034, 9058; and from the meaning of 'dying' as being wiped out. The reason why truth and good are meant here is that 'the thief' or 'the theft' means that which has been taken away, thus good and truth, as also in the words that follow in verse 4, If the theft is certainly found in his hand, whether it is ox or ass, or member of the flock, [and they are] alive ... 'Ox', 'ass', and 'member of the flock' mean exterior and interior forms of good and truths; and they are called 'the theft' because they are in the thief's hand. The like applies to silver and vessels in verse 7, in that these as well mean interior and exterior truths. 'The thief' has the same meaning as 'the theft' because in the abstract sense, in which things are understood in abstraction from a person, 'the thief' is the theft, that is, the truth or good that has been taken away, see immediately above in 9125.