حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، كَانَ يَقُولُ أُصَلِّي صَلاَةَ الْمُسَافِرِ مَا لَمْ أُجْمِعْ مُكْثًا وَإِنْ حَبَسَنِي ذَلِكَ اثْنَتَىْ عَشْرَةَ لَيْلَةً ‏.‏

Yahya related to me from Malik from Ibn Shihab from Salim ibnAbdullah that Abdullah ibn Umar used to say, "I pray the prayerof atraveller as long as I am undecided whether to remain somewhere ornot, even if I am detained for twelve nights." Translation Not Available

Book Ref: Muwatta Imam Malik Book 9 Hadith 346
Web Ref:  Muwatta Imam Malik Book 9 Hadith 18