ENOfficial
Narrated Muhammed b. Ja'far: On the authority of 'Awf: 'Iyafah means to makes the birds fly by threatening them. Tarq means lines drawn on the earth.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا ابْنُ بَشَّارٍ، قَالَ قَالَ مُحَمَّدُ بْنُ جَعْفَرٍ قَالَ عَوْفٌ الْعِيَافَةُ زَجْرُ الطَّيْرِ وَالطَّرْقُ الْخَطُّ يُخَطُّ فِي الأَرْضِ .
sunnah.com