It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that we were in a battle (Mu'tah) when the people suddenly fled. We said, "How will we face the Prophet (peace and blessings be upon him) when we have fled from the battlefield?" Then this verse was revealed: «إِلَّامَنْتَوَلَّىٰلِلْقِتَالِ»[الأنفال: 16] "Except for one who turns aside to fight." We said, "We will not go to Madinah so that no one sees us." Then we said, "If we go (it would be better)." The Prophet (peace and blessings be upon him) finished the Fajr prayer, so we said, "We are fugitives." The Messenger of Allah (peace and blessings be upon him) said, "You are those who will return to attack, not those who flee." Then we kissed the blessed hand of the Prophet (peace and blessings be upon him). He said, "I am your central figure; you should come to me."
Benefits and Issues: This narration is weak in terms of its chain of transmission; however, the scholars have deemed it permissible, out of love, to kiss someone’s hand or head due to their knowledge, practice, righteousness, and piety.
Source: Fadlullah al-Ahad: Urdu Commentary on al-Adab al-Mufrad, Page: 972