|The Eastern Gate of Jerusalem|
One of the approaches is allegorical interpretation which seeks to find deeper spiritual truths by identifying symbolic meanings in the Biblical texts. It is an ancient method that began with the early church theologian and write Origen of Alexandria. An example of this is interpreting Aaron, the first High Priest in the Old Testament, as a symbol of Jesus Christ, the spiritual High Priest. The Bible does contain allegories that are clearly identified in context (see Paul's interpretation of Hagar and Sarah in Gal. 4: 21-24). The allegorical method of interpretation can be controversial when it stretches a bit too far and/or when it ignores the context of the verses in the larger text.
Which brings me to the symbolic meaning of the names of the gates of Jerusalem as described in Nehemiah 2: 11-20. There are as many interpretations as there are people who have offered them as you will see if you look for this on google!
The gate names all have literal meanings of course. The sheep gate is where the shepherds brought the sheep into the city for market; the fish gate is where the fishermen from the Sea of Galilee brought their catch of the day for sale; the Horse gate admitted the horses; the Dung Gate was where the city's refuse was dumped and so forth.
Some common allegorical meanings often ascribed to the gates are:
Sheep Gate =Jesus Christ the Good Shepherd
Fish Gate ="fishing" for men
Fountain Gate and the Water Gate =the fountain of Living Water (the Holy Spirit)
Horse Gate=spiritual warfare (horses were used in warfare)
East Gate = place where the Messiah will return (taken from Zec. 14: 4 which says the Messiah will return on the Mount of Olives east of Jerusalem)
Dung Gate = sin which smells bad and causes decay
Some interpreters also find in the order in which the gates were repaired an allegory of the life of faith in Christ and the shape of the wall and the gates is compared to a heart or a footprint both of which allude to Christ's presence.
Generally I favor the "plain meaning of the text" school of Biblical interpretation, but sometimes looking for allegorical meanings can deepen the power of the Word and our understanding of it.