He is saying: Obayoao Amir Almoamnin Abi Bakrin AlQuraishi Ala alsamei waltaa' fi Almanshati wa Almakrah walosri walyosr wa ala iqamati din Allah wa jihad adoi Allah wa ala iqamati Aldawla Alislamiya waldab Anha Wa Allaho Ala ma Akolo Shahed Allah yatqabal mini wamink أبايع أمير المؤمنين أبى بكر القريشى على السمع والطاعة فى المنشط والمكره والعسر واليسر وعلى إقامة دين الله وجهاد عدو الله وعلى إقامة الدولة الإسلامية والدب عنها والله على ما أقول شهيد الله يتقبل منى ومنك I gave baya to Abubar AlQurashi on obedience in good and bad (in active and in bad) ,on the establishment of the Deen of Allah, Jihad the enemies of Allah and the establishment of the Islamic country and Allah witnesses what I say. Allah accept from me and you.

It's kind of a promise to obey everything the leader says unless the leader disobey Allah.