Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
bukhari:4309Muḥammad b. Bashhār > Ghundar > Shuʿbah > Abū Bishr > Mujāhid > Ibn ʿUmar Innī Urīd > Uhājir > al-Shaʾm

I said to Ibn ʿUmar, "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."  

البخاري:٤٣٠٩حَدَّثَنِي مُحَمَّدُ بْنُ بَشَّارٍ حَدَّثَنَا غُنْدَرٌ حَدَّثَنَا شُعْبَةُ عَنْ أَبِي بِشْرٍ

عَنْ مُجَاهِدٍ قُلْتُ لاِبْنِ عُمَرَ ؓ إِنِّي أُرِيدُ أَنْ أُهَاجِرَ إِلَى الشَّأْمِ قَالَ لاَ هِجْرَةَ وَلَكِنْ جِهَادٌ فَانْطَلِقْ فَاعْرِضْ نَفْسَكَ فَإِنْ وَجَدْتَ شَيْئًا وَإِلاَّ رَجَعْتَ