عَنْ أَبِي أُمَامَةَ رَضِيَ اللَّهُ عَنْهُ عَنِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَ ((مِنْ تَمَامِ عِيَادَةِ الْمَرِيضِ أَنْ يَضَعَ أَحَدُكُمْ يَدَهُ عَلَى جَبْهَتِهِ أَوْ يَدِهِ فَيَسْأَلَ كَيْفَ هُوَ وَتَمَامُ تَحِيَّاتِكُمْ بَيْنَكُمُ الْمُصَافَحَةُ))
It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: The complete manner of visiting a sick person is that one should place his hand on the patient's forehead or hand and then ask about his condition, and the complete greeting is that one should also shake hands.