It was narrated that `Ali (رضي الله عنه) said: The Messenger of Allah (ﷺ) sent me, az-Zubair and Abu Marthad on a mission, and we were all horsemen. He said: “Set out until you reach Rawdat Khakh` - this is how Abu `Awanah said it - “and there you will find a woman who has a letter from Hatib bin Abi Balta`ah to the mushrikeen.” And he quoted the hadeeth at length.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا عَفَّانُ، حَدَّثَنَا أَبُو عَوَانَةَ، حَدَّثَنَا حُصَيْنٌ، حَدَّثَنِي سَعْدُ بْنُ عُبَيْدَةَ، عَنْ أَبِي عَبْدِ الرَّحْمَنِ السُّلَمِيِّ، عَنْ عَلِيٍّ، رَضِيَ اللَّهُ عَنْهُ قَالَ بَعَثَنِي رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَالزُّبَيْرَ وَأَبَا مَرْثَدٍ وَكُلُّنَا فَارِسٌ فَقَالَ انْطَلِقُوا حَتَّى تَبْلُغُوا رَوْضَةَ خَاخٍ كَذَا قَالَ أَبُو عَوَانَةَ فَإِنَّ فِيهَا امْرَأَةً مَعَهَا صَحِيفَةٌ مِنْ حَاطِبِ بْنِ أَبِي بَلْتَعَةَ إِلَى الْمُشْرِكِينَ وَذَكَرَ الْحَدِيثَ بِطُولِهِ.
sunnah.com