What is the ruling on the mizmar (a wind instrument), and what is the authenticity of the hadith: "The saliva of a believer is a cure for a believer"?

The ruling on wind instruments and music is explained in fatwas: 32461 and 32787. As for the hadith: "The saliva of a believer is a cure for a believer," it has no origin, but its meaning is sound. For it is in the Two Sahihs that when a person complained of something, or had a sore or a wound, the Prophet, peace and blessings be upon him, would place his finger on the ground, then raise it and say: "In the name of Allah, the dust of our earth with the saliva of some of us, our sick are cured by the permission of our Lord."