Allah's Statement "And what is wrong with you that you fight not in the Cause of Allah... (till) ... whose people are oppressors..." (V.4:75) Sahih al-Bukhari 4587
Arabic hadith text
حَدَّثَنِي عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ، حَدَّثَنَا سُفْيَانُ، عَنْ عُبَيْدِ اللَّهِ، قَالَ سَمِعْتُ ابْنَ عَبَّاسٍ، قَالَكُنْتُ أَنَا وَأُمِّي، مِنَ الْمُسْتَضْعَفِينَ.
Translation
Narrated Ibn `Abbas
My mother and I were among the weak and oppressed (Muslims at Mecca).