Bismillaah Al-Hamdulillaah wa salatu wa salaamu 'ala rasulullaah
Amma-ba'd
'Umar Ibnul Khattaab (radiallaahu Ta'aala 'anhu) said:
"If one of you knew what he has in saying to his (Muslim) brother [جَزَاكَ اللَّهُ خَيْرًا] - Jazak Allaahu khairan - you would have increased in saying it to one another." [Musannaf Ibn Abee Shaybah, no. 26519]