In Zechariah 2:4, this signifies the church of people who will receive the Divine proceeding of the Lord on a deep level within themselves. (Apocalypse Explained 629[6])

7533. 'And Jehovah made Pharaoh's heart unyielding' means that they remained obstinate. This is clear from the meaning of 'the heart being made unyielding', 'hardened', and 'stubborn' as obstinacy, dealt with in 7272, 7300, 7305. When it says that Jehovah made his heart unyielding the meaning in the internal sense is not that Jehovah but that they themselves made their heart unyielding, that is, remained obstinate. For the evil present with a person is what makes him unyielding or obstinately opposed to Divine things. Such evil comes out of the person himself; and it enters him from hell, not from heaven. Nothing but good can enter him from the Lord by way of heaven; evil cannot emanate from good, still less from Goodness itself. Evil emanates from origins of its own, that is to say, from the opposites of love to God and love towards the neighbour. Such origins reside with man, not at all with God. From this it is evident that when it states in the Word that God causes something bad to happen, it is a statement made in accordance with outward appearances. But for more on these matters see 2447, 6991, 6997.