Praise be to Allaah.
The Prophet (peace and
blessings of Allaah be upon him) taught us to rewards the one who does us a
favour, and if we cannot do that then we should pray to Allaah for him and
say: Jazaak Allaahu khayran (may Allaah reward you with good).
Abu Dawood (1672) narrated
that ‘Abd-Allaah ibn ‘Umar (may Allaah be pleased with him) said: The
Messenger of Allaah (peace and blessings of Allaah be upon him) said:
“Whoever does you a favour, then reciprocate, and if you cannot find
anything with which to reciprocate, then pray for him until you think that
you have reciprocated him.” Classed as saheeh by al-Albaani in Irwa’
al-Ghaleel (1617).
Al-Tirmidhi (2035) narrated
that Usaamah ibn Zayd (may Allaah be pleased with him) said: The Messenger
of Allaah (peace and blessings of Allaah be upon him) said: “Whoever
has a favour done for him and says to the one who did it, ‘Jazak Allaahu
khayran,’ has done enough to thank him.” Classed as saheeh by al-Albaani in
Saheeh al-Tirmidhi.
“has done enough to thank
him” means: he has thanked him sufficiently, by acknowledging his
shortcoming and his inability to reward him, so he defers his reward to
Allaah so that He might reward him abundantly.
This is the wording that
was narrated from the Prophet (peace and blessings of Allaah be upon
him), “Jazak Allaahu khayran (may Allaah reward you with good)”, and this is
undoubtedly more perfect than any other. The best of guidance is the
guidance of the Prophet (peace and blessings of Allaah be upon him) so
we should not ignore this and use something else instead.
If the Muslim says Jazakum
Allaahu alfa khayrin (May Allaah reward you with good one thousand times)
occasionally, there is nothing wrong with it, so long as he accepts that the
wording of the Prophet (peace and blessings of Allaah be upon him) is
more perfect and better.
And Allaah knows best.