1. Exposition

Why was timber laid in the walls?

Ezra 5:8 (ESV)

8 Be it known to the king that we went to the province of Judah, to the house of the great God. It is being built with huge stones, and timber is laid in the walls. This work goes on diligently and prospers in their hands.

The technique of laying timber (wood) between layers of stone or brick was common in the ancient Near East. It was probably used as a means of strengthening buildings against earthquakes as well as to help bond the building.