Sahih al-Bukhari 4309
صحيح البخاري#4309Sahihحَدَّثَنِي مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا غُنْدَرٌ، حَدَّثَنَا شُعْبَةُ، عَنْ أَبِي بِشْرٍ، عَنْ مُجَاهِدٍ، قُلْتُ لاِبْنِ عُمَرَ ـ رضى الله عنهما ـ إِنِّي أُرِيدُ أَنْ أُهَاجِرَ إِلَى الشَّأْمِ. قَالَ لاَ هِجْرَةَ وَلَكِنْ جِهَادٌ، فَانْطَلِقْ فَاعْرِضْ نَفْسَكَ، فَإِنْ وَجَدْتَ شَيْئًا وَإِلاَّ رَجَعْتَ.
Narrated Mujahid:I said to Ibn `Umar, "I want to migrate to Sham." He said, "There is no migration, but Jihad (for Allah's Cause). Go and offer yourself for Jihad, and if you find an opportunity for Jihad (stay there) otherwise, come back
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 64:340