Sunan Abi Dawud, Hadith 3908

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.

حَدَّثَنَا ابْنُ بَشَّارٍ، قَالَ قَالَ مُحَمَّدُ بْنُ جَعْفَرٍ قَالَ عَوْفٌ الْعِيَافَةُ زَجْرُ الطَّيْرِ وَالطَّرْقُ الْخَطُّ يُخَطُّ فِي الأَرْضِ ‏.‏

sunnah.com

also referenced under: Hadith 3899 (Hasan)