Li'alla ya'lama Ahlul kitaabi allaa yaqdiroona 'alaa shai'im min fadlil laahi wa annal fadla bi Yadil laahi u'teehi many yashaaa'; wallaahu Zul fadilil 'azeem
(You should do this) so that the People of the Book know that they have no control over Allah's Bounty, and that all bounty is in Allah's Hand; He bestows it on whomsoever He pleases. Allah is the Lord of abounding bounty.
