In the chapter about the Prophets in his Sahih, under, "The Descent of `Isa, Son of Maryam,'' Al-Bukhari recorded that Abu Hurayrah said that the Messenger of Allah said,

«وَالَّذِي نَفْسِي بِيَدِهِ، لَيُوشِكَنَّ أَنْ يَنْزِلَ فِيكُمُ ابْنُ مَرْيَمَ حَكَمًا عَدْلًا، فَيَكْسِرَ الصَّلِيبَ، وَيَقْتُلَ الْخِنْزِيرَ، وَيَضَعَ الْجِزْيَةَ، وَيَفِيضَ المَالُ حَتَّى لَا يَقْبَلَهُ أَحَدٌ، حَتَّى تَكُونَ السَّجْدَةُ خَيْرًا لَهُمْ مِنَ الدُّنْيَا وَمَا فِيهَا»

(By Him in Whose Hands my soul is, the son of Maryam (`Isa) will shortly descend among you as a just ruler, and will break the cross, kill the pig and abolish the Jizyah. Then there will be an abundance of wealth and nobody will accept charitable gifts any more. At that time, one prostration will be better for them than this life and all that is in it.) Abu Hurayrah then said, "Read if you will,

﴿وَإِن مِّنْ أَهْلِ الْكِتَـبِ إِلاَّ لَيُؤْمِنَنَّ بِهِ قَبْلَ مَوْتِهِ وَيَوْمَ الْقِيَـمَةِ يَكُونُ عَلَيْهِمْ شَهِيداً ﴾

(And there is none of the People of the Scripture, but must believe in him, before his death. And on the Day of Resurrection, he will be a witness against them.)'' Muslim recorded this Hadith. So, Allah's statement,

﴿قَبْلَ مَوْتِهِ﴾

(before his death) refers to the death of `Isa, son of Maryam.