Laying the Cornerstone

We know that at a הנחת אבן הפנה, cornerstone-laying, we are accustomed that a great person places the first stone.

Fascinatingly we find mention of this where it says ויבן שאול מזבח לה' אתו החל לבנות מזבח לה', Shaul built a mizbeach to Hashem; this was the first of the mizbeachos that he built to Hashem.

The Redak cites a Midrash that Shaul was the one began to build (החל לבנותו) this mizbeach, meaning he himself put the first stone and afterwards the builders built the mizbeach until its completion.