Abu Hurayra reported that the Prophet, may Allah bless him and grant him peace, said, "Give gifts and you will love one another."  

عَنِ النَّبِيِّ ﷺ يَقُولُ تَهَادُوا تَحَابُّوا  

Anas said to his son, Thabit, "My son, exchange gifts, it will bring about love between you."  

عَنْ ثَابِتٍ قَالَ كَانَ أَنَسٌ يَقُولُ يَا بَنِيَّ تَبَاذَلُوا بَيْنَكُمْ فَإِنَّهُ أَوَدُّ لِمَا بَيْنَكُمْ