جزاكم الله خير الجزاء
Jazākum Allāhu khayra al-jazāʾ
Topic
“May God grant you the best reward”: an expression of thanks to someone who has given a gift or done a service.
What it means
The words mean “May God repay you with the best of repayments.” Muslims say them to thank anyone who has given something or helped. The form with -kum addresses several people, while jazāka Allāhu khayran addresses one man, and jazāki Allāhu khayran one woman. The speaker leaves the reward to God, who can give more than any person can. Al-Tirmidhi reports a saying of the Prophet (peace be upon him) that whoever is shown kindness and says to the giver “May God reward you with good” has done the utmost in praise. Muslims use the phrase in many settings and often as a reply to a favour. It sits alongside the plain shukran, “thank you”, which Muslims also use.
Term and Arabic as listed in Ismail al Faruqi, Toward Islamic English (International Institute of Islamic Thought, 1995), p. 60, listed as JAZĀKUM ALLAH KHAYR AL JAZĀ’.. The definition is restated here.