Mishkat al-Masabih 10 The Rites of Pilgrimage كتاب المناسك 32

وَعَنِ ابْنِ عُمَرَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِذَا لَقِيتَ الْحَاجَّ فَسَلِّمْ عَلَيْهِ وَصَافِحْهُ وَمُرْهُ أَنْ يَسْتَغْفِرَ لَكَ قَبْلَ أَنْ يَدْخُلَ بَيْتَهُ فَإِنَّهُ مَغْفُورٌ لَهُ» . رَوَاهُ أَحْمد

Ibn ‘Umar reported God’s messenger as saying, “When you meet one who has performed the pilgrimage, greet him, shake hands with him and tell him to ask forgiveness for you before he enters his house, for he has been forgiven.” Ahmad transmitted it.