A variable plane is at a constant distance \(p\) from the origin \(\mathrm{O}\) and meets the set of rectangular axes \(\mathrm{OX}_{i}\) \((i=1,2,3)\) at points \(\mathrm{A}_{i}\) \((i=1,2,3)\), respectively. If planes are drawn through \(\mathrm{A}_{1}\), \(\mathrm{A}_{2}\), \(\mathrm{A}_{3}\), which are parallel to the coordinate planes, then the locus of their point of intersection is :