For the Lie algebra $\mathbf{sl}_2$ over a $p$-adic field, the Fourier transform of a regular orbital integral is expressed as an integral over all regular orbital integrals, with explicit coefficients. This expression, unlike the Shalika germ expansion, is not restricted to orbits of small elements. The result gives quite an elementary access to a simple example of Waldspurger's recent theorem on endoscopic transfer of the Fourier transforms.