Final answer:
A foundation must be set up before constructing a masonry wall, especially for ashlar masonry, to ensure structural stability and durability.
Step-by-step explanation:
A foundation must be established prior to masonry wall construction. When constructing a wall with ashlar masonry, a specific stone construction technique where stones are meticulously cut and arranged in a rectilinear pattern, it is critical to lay a stable foundation. Foundations distribute the weight of the structure and ensure that the construction is both stable and durable. When using traditional materials such as wood, brick, stone, or mud bricks, the importance of a solid foundation cannot be overstated, especially in stone construction methods like the post and lintel system seen at historical sites like the Palace of Karnak.