It is mentioned in Khasaais-e-Kubra on the authority of Hadhrat ‘Ali (May Allah be well pleased with him), he says: The Holy Prophet (Sallallahu alaihi wa sallam) was sending me as a judge to Yemen. I requested: O Prophet of Allah (Sallallahu alaihi wa sallam)! You are sending me to a community wherein there are many elder folk and I am young. I don’t even know how to judge. The Holy Prophet (Sallallahu alaihi wa sallam) placed His hand on my chest and supplicated: O Allah! Teach him how to judge.
Hadhrat ‘Ali (May Allah be well pleased with him) says: By the Lord Almighty! After this, I never had any doubt when judging between 2 persons.
It was the effect of the blessed hand of the Holy Prophet (Sallallahu alaihi wa sallam) that among the Companions there was no better judge than Hadhrat ‘Ali (May Allah be well pleased with him), as attested to in many other Traditions.
There is no doubt that the supplications of the Holy Prophet (Sallallahu alaihi wa sallam) on these occasions were all accepted and by the command of Allah Most High, the effect was seen. Even the placing of the hand was not without reason, otherwise, the Holy Prophet (Sallallahu alaihi wa sallam) would simply raise His hands as was His custom. Placing the hand on the chest suggests that to enlighten, the Holy Prophet (Sallallahu alaihi wa sallam) placed His hand on Hadhrat ‘Ali’s (May Allah be well pleased with him) chest. The supplication was made for this very purpose and in this world of means and reasons material means are also necessary. That’s why the Holy Prophet (Sallallahu alaihi wa sallam) placed His hand, so that its effect should also be there. This shows that the way medicines, etc. have their effect in this material world, in the same way, the blessed hand of the Holy Prophet (Sallallahu alaihi wa sallam) also has an effect, which is proven by numerous Hadith.
It is mentioned in Khasaais-e-Kubra that Bishr bin Mu’awiya says: I went to the Holy Prophet (Sallallahu alaihi wa sallam) along with my father. He caressed my head and prayed for me. Wherever the blessed hand of the Holy Prophet (Sallallahu alaihi wa sallam) touched me, those area became distinct and radiant.
That radiance was not present in the blessed hand of the Holy Prophet (Sallallahu alaihi wa sallam) that it got transferred to Bishr bin Mu’awiya and neither was it hidden in his body which the Holy Prophet (Sallallahu alaihi wa sallam) caused to expressed. Instead, that radiance was created by the blessed hand of the Holy Prophet (Sallallahu alaihi wa sallam). This was the effect of the blessed hand of the Holy Prophet (Sallallahu alaihi wa sallam) whose power extended to the realm of nonexistence as well.
[Excerpted from Maqasid Ul Islam, Vol. 9, Pg. No. 17, 18]