Let's draw out our pictures. Let's suppose that Be forms this hybridized orbital, and then this hybridized orbital interacts with the H atom to form our covalent bond. And let's also suppose that we have a Beryllium atom that donates a simple two P orbital to interact with that H atom. Let's see which one is more stable. Well, recall that whenever bonds are formed, bonds or covalent bonds are formed by the overlap of atomic orbitals, as we see here. And we know that the better the overlap, the larger the lobes, the more stable our compound is, the more stable our bond is.