Sunan Abi Dawud 22062
In-book no 1558حَدَّثَنَا ابْنُ السَّرْحِ، وَسُلَيْمَانُ بْنُ دَاوُدَ، قَالاَ أَخْبَرَنَا ابْنُ وَهْبٍ، أَخْبَرَنِي يُونُسُ، عَنِ الزُّهْرِيِّ، قَالَ قَالَ أَبُو بَكْرٍ إِنَّ حَقَّهُ أَدَاءُ الزَّكَاةِ وَقَالَ عِقَالاً .
This tradition has also been transmitted by Al Zuhri through a different chain of narrators. This version has “Abu Bakr said its due is the payment of zakat.” He used the word “a rope of a Camel”