It was narrated that 'Abdullah bin As-Sa'di said:

"We came in a delegation to the Messenger of Allah and my companions entered and asked their questions. I was the last of them to enter, and he said: 'What is you question?' I said: 'O Messenger of Allah, when will emigration end?' The Messenger of Allah said: 'Emigration will not cease so long as the disbelievers are being fought."'

أَخْبَرَنَا مَحْمُودُ بْنُ خَالِدٍ، قَالَ حَدَّثَنَا مَرْوَانُ بْنُ مُحَمَّدٍ، قَالَ حَدَّثَنَا عَبْدُ اللَّهِ بْنُ الْعَلاَءِ بْنِ زَبْرٍ، قَالَ حَدَّثَنِي بُسْرُ بْنُ عُبَيْدِ اللَّهِ، عَنْ أَبِي إِدْرِيسَ الْخَوْلاَنِيِّ، عَنْ حَسَّانَ بْنِ عَبْدِ اللَّهِ الضَّمْرِيِّ، عَنْ عَبْدِ اللَّهِ بْنِ السَّعْدِيِّ، قَالَ وَفَدْنَا عَلَى رَسُولِ اللَّهِ ﷺ فَدَخَلَ أَصْحَابِي فَقَضَى حَاجَتَهُمْ وَكُنْتُ آخِرَهُمْ دُخُولاً فَقَالَ " حَاجَتُكَ " . فَقُلْتُ يَا رَسُولَ اللَّهِ مَتَى تَنْقَطِعُ الْهِجْرَةُ قَالَ رَسُولُ اللَّهِ ﷺ " لاَ تَنْقَطِعُ الْهِجْرَةُ مَا قُوتِلَ الْكُفَّارُ " .